On Wednesday we got in line at 9:22 and got into meet her at 10:00 (we were the last family before her first break). I would recommend skipping Buzz & Woody. They start meeting right at 9:00 and their line was 60 minutes almost immediately at park opening (probably because people jumped into their line right after getting a TSM FP since the SB wait for TSM was already an hour as well).
H&V seems to be more of a meal geared toward boys...all of the characters are boys except for June from the Little Einsteins. I wouldn't expect both Sofia and Doc to replace two of the characters...maybe one will replace June eventually, but I can't see the meal being so heavy on the girly stuff.
I didn't even think about this, good point. I guess I just thought that they would eventually put the top Disney Junior characters in the rotation... Jake, Sofia and Doc. My DD is 7, so she is starting to get a little 'old' for Disney Junior, but those are the only shows she watches on that channel.
Either way, we won't be giving up our reservation because of all the wonderful character experiences I have heard about there.