I'd definitely like to see less humanoid beast races this time around. In Oblivion there was hardly any point to them at all. And reptiles with briasts? Really??!!
Then again, while I'm dreaming, I'd also like the chance to play as an Alfiq mage ("http://www.imperial-library.info/content/oblivion-mixed-unit-tactics"). Now that would be some challenging roleplay! An exceedingly stealthy, magic powerful character able to get through gaps too small for any NPC or monster, but on the downside, unable to use weapons or tools, unable to wear anything except (possibly) an amulet, unable to talk to anyone except other Khajiit...
A perfect Imperial spy
.
Sadly, I fear even non-humanoid beast races are unlikely, except (possibly) as single-mesh NPCs.