The bottleneck for a MMORPG is skeleton animation’s matrix calculation. hower, in SM2.0 it is hard to solve.
Here is a proposal for cpu free algorithm: https://developer.nvidia.com/content/mesh-skinning (Vertex offset method)
I wonder this method need a pre-calculation for each bone matrix, and without interplation between matrix.

Away3D skeletal animation does do hardware skinning.  However, due to limitations of Stage3D, your skeletons/animations are limited to a maximum of 4 bone (joint) weights per vertex, and a maximum of ~42 bones (joints) (128 vertex constant registers, divided by 3 constants per bone).

If you go above these limitations, away3d will fall back to calculating vertex positions on the CPU.

Thx for quick reply.
As I mentioned above, pre-calculation of matrix maybe better. This part of calculation maybe solved by FlasCC.
BTW, bone numbers may also be improved, cause only 6 floats(without scale) is enough for most games.