From BlenderWiki

[edit] Blender 2.46a TODO (bugfix release)

• Bring Back UV Set/Clear Menu (Was key, can be Alt+W?), and Texture face copy buttons.
• Game Enginee will always corrupt pose data constraints
  https://projects.blender.org/tracker/index.php?func=detail&aid=13605&group_id=9&atid=125
• PyNodes will run scripts even when "Enable Scriptlinks" is disabled or -y is passed. (No way to disable, security flaw)
• Y and Z axes on SpaceNavigator are swapped when using transform mode.

[edit] Blender 2.46 TODO (Its over!)

Here are a list of issues that need to be resolved before 2.46 release. Unlike the bug tracker this should be used for features that are incomplete or made unstable since 2.45 release.

[edit] Python

• Python api needs to adhere to user preferences object adding preferences (editmode/align) - Campbell

[edit] .B.blend

• set the default initial editmode and orientation in the default .B.blend - Campbell

[edit] Rendering

• Raytracing is currently slower then it used to be (because of mallocs within the raytraced rendering code, added since 2.45) - Brecht
• Image thread locking slows down rendering on mac's - Brecht

[edit] Display

• NDof, can set the view dist value to zero making zooming with the mouse wheel stop working - lukep

[edit] UV Mapping

• Alt Right click can not create seams since uv editing was merged with editmode. - Campbell
• Preserve image aspect option messes up with pinned UV's - Brecht

[edit] Particles

Remove old static particles since they are not used anymore (PAF_* and can then remove DNA_object_types sumohandle pointer) - Campbell

[edit] Animation

• Implement NLA modifier (Oomph) or remove it from the menu. [this was already like this for previous releases, so not really a show-stopper for release] - Algorith
• IPO smooth which currently gives odd results - Algorith
• NLA currently has destructive bugs which can destroy keyframes

[edit] Particles API

• Need at least a minimalist particles API for renderer and other exporters to continue working with 2.46 - there is a patch in the tracker but still requires some cleaning and fixes - Pidhash