I generally prefer to level in the TBC starting zones. The Quest drops from those areas are so much better than the other starting zones. As what everyone else has said, the new changes to xp gain from 20-60 as well as quest xp from 30-60 makes leveling A LOT easier. And I should know, I have too many alts and its a big noticeable jump.

Good luck with your char!

I saw something about elite mobs in dungeons for 1-60 are tweaked for solo play... anyone can elaborate?

Not sure about this....currently having SPM so I hold back on WoW...but what I think that they said they will tweak elite mobs in dungeons might mean that:

a)They have nerfed all elite mobs for Pre-TBC
b)Mobs in dungeons are no longer Elite
c)The number of mobs are reduced
d)You are much stronger now
e)A combination of both or more

As i said I haven't play WoW in patch 2.3 yet so I can only speculate

still waiting for the right time to play wow, huhuhuh, so busy with work lately.