Most popular ideas today

When you have not saved your file, have blender ask if you want to quit when closing blender via the windowmanager. (useually cross button)
- This is common for most applications

When you render - you do not see the current state of rendering... in best cases you see last render time and current part-number...

But what about current render state in percent (for image or animation)? Or current render time for current frame. Or estimated time for frame / animation?

Look at this screen - wow!
http://images.gamedev.net/features/reviews/modo202/5-shot-glass-render.jpg

multi-threaded fluid simulation
multi-threaded cloth simulation
multi-threaded preview render
multi-threaded playblast render

another nice update for the preview renderer would be (as seen in modo) to render like a progressive jpeg. so the longer you wait the clearer the render gets. this lets you have preview open all the time on a seperate view and constantly see your changes

a way for deleting (all) unused datablocks of the current blender session so that you don't have to restart blender anymore for that.

True support for Ngons, allowing a much faster box modeling work flow for those who choose to use them. I can see possibilities of benefits for architectural modeling as well as organic modeling.

It would be really great to be able to see particles/halo textures in raytraced reflections & through transparent materials.

Give the user visual feedback concerning the kind of unit he/she is working in. More specifically, being able to set one blender unit as meteres, centimeters, kilometers, inches, feet, etc.
Adjustments should be updated in the information bar in the 3d window (for instance when moving an object, you see how many mm or cm it has moved)
Further, when turning on display selected edge length, the current unit should be added to the shown numbers, so when you select an edge, its says 0.5 mm instead of 0.5.

As extra maybe make it possible to render the 'display selected edge length' (may be interesting for architects?)

If an object/material/texture property is animated, (for example there is an ipo curve for Material RGB), then on the panel where the user usually sets that property (Materials panel) is grayed out or a darker shade as a visual cue.

If the user changes the property by moving the slider or entering a value, a popup window asks them if they want to establish a new key, or ignore the entry.

see http://wiki.blender.org/Requests

Currently blender has (among others) a "Solid" and a "Wireframe" view-mode. Why not combine them to a extra view-mode?

(For an example look here: http://www.ag-systems.net/mxw/book_wire.jpg)

An infinite plane is a plane that spans an infinite distance. This would be very useful, especially when making landscape scenes with Blender.
After trying Bryce 5.5, I found that the infinite plane feature was the one I used the most. I would love to see something like this in Blender!

It would be wonderful if drag and drop could be used for all of the places it makes sense. This includes drag and drop video seqeunces and audio sequences on the video sequencer.

Drag and drop textures onto objects.

Drag and drop ordering for outliner, etc.

The developers of Freestyle , a non-photorealistic renderer, have suggested that their renderer be integrated into Blender. Showing support for its implementation, here is one user's request to accompany the request of Freestyle's developers.

http://freestyle.sourceforge.net/

The filter that shows only specific type of file in browser: only *.blend, only images, only *.png etc..

Some way of switching cameras in an animation so as to do jump cuts. Typically one wants to have frames 1-23 from camera #1 (long shot, say), then frames 24-35 from camera #2 (medium shot), and then frames 36-62 from camera #3 (close up on girl's face)... and then for frames 7500-7525 back to camera #1 for the close out. There is no way to do this in Blender at them moment. OK, there are various expedients, such as jumping the camera location between frames (doesn't work, looks terrible, eg if one does interlacing) or a script (hard to manipulate).

It would be nice if one could correct a vote after it has been cast. Maybe clicking the right arrow in the first place went a bit wrong, now you voted for while you wanted to vote against. Or maybe an idea got improved with a very good Feature Request that explains it All.

What I think of is a sort of a mix between painting a UV map and using the sculpt tool.
It might be less computer-intensive to have some tools in the image editor that would mimick the sculpt brushes when editing a normal map.
This would be used like "sculpt" while keeping a small number of faces.

Paint and projections across object seams to eliminate/alleviate UV tweaking... and it would just be fantastic to project decals onto your model/texture.

something i think that would take Blender more over-the-top than it already is would be muscle, and perhaps even skin, simulation.

check out

http://www.cgcharacter.com/cgskin.html

http://cgtoolkit.com/muscletk.htm

Especially when working with mirror modifier, it'd be great to be able to quickly set a location of a vertex to zero with a certain axis (usually x) when working with center vertices. This can be done with the n-menu (transform properties) but it requires using the mouse and it's not a single function (not fast, not hotkey, a menu).

Also sometimes you might want to clear the rotation or the scale on a certain axis only.

In edit mode it'd work in the object's local co-ordinates, I believe (rotation and scale are probably unusable, unless you count face normals, and that's only for the rotation angle of a face).

It'd work like this:

press alt+g
-->
menu item 1: clear location
menu item 2. clear loc X (would be toggled with XKey)
menu item 3. clear loc Y (would be toggled with YKey)
menu item 4. clear loc Z (would be toggled with ZKey)

Same with rotation and scale.

the sculpting tool has a number of nice ideas for interaction (scaling and intensity of the brush), usage of textures for brushes, and brush mirroring - it would be excellent if these ideas could be propagated to the rest of the painting tools.