Totally not trying to be snub here, but it seems we go through this each year.
The figures shown at SDCC are final sculpts. There won't be any changes to them. While we have occasionally been able to make small paint changes (like adding purple to BA Skeletor's feet) any sculpt change is not possible.
In regard specifically to BG Evil Lyn (who seems to have gotten the lion's share of change requests) let me see if I can clarify.
We actually costed out a new tunic outfit for her. It was the Horsemen who wanted from a design stand point (I presume to keep the "Classics look") to go with a repaint of the "Teela tunic". I've mentioned before, we don't art direct the Horsemen in this way. Her look is the artistic choice of the Horsemen.
And for the Sorceress who also has a lot of change requests; her paint scheme was designed by the Horsemen. I asked them and design about this (vs. the more Filmation orange inside color fans are asking about) and they felt strongly that this look worked better for a figure (vs. a drawn cartoon) and are really happy with the way she worked out. This is also the request for a new"Spell casting hand" or to use Catra's hand for Sorceress. She was designed by the Horsemen as is and that is how they and design want to go.
Hope this helps clarify. While you can't please everyone all the time, I think Terry and the Four Horsemen have done a bang up job on each and every upcoming figure. In particular I can't wait for Fisto and Kahn. Two figures I had as a kid and really enjoyed!
-Oh, and keep sending in those entries for the 2012 contest. We've already received some and we couldn't be more excited!