After Effects or Flash. Unfortunately there isn't an open source solution, as Inkscape doesnt have an animation engine (but it should). I guess you could just animate textured planes in Blender though...
I was wondering what programs are used for moving graphics for opening credits. You know like the James Bond intro's and such. I think it was Quantum of Solace or the one before it. Where they had all the nice 2d ladies in the sand. Also what do you thing was used for the Zero Punctuation video game reviews? Thanks.
I haven't used it yet, but looking at the documentation one workflow looks like you sketch out your animation on a bitmap layer(s). Then go back and trace it all on vector layer(s), and finally export the vector layers as an animation. Though you could forgo that and export a bitmap based PNG sequence or Quicktime movie…
although, if you are savvy enough with ActionScript3, you can use flashdevelop and the flexSDK to produce script based animation without owning Flash. You can embed external bitmaps, although all your text layout and shape creation would be code-based. You can do some pretty kicking animation and sequencing with the…
I'm not sure what you are after but maybe Pencil would be useful. Apparently it can be used for both vector and bitmap based animation. It can also export image sequences, and Flash SWFs. Best of all it's open source.