Yeah, the thing about seiyuu is, there are some very experienced ones who can do voices for practically characters of all sorts of personality.
For instance, did you know the voice cast for Hinoto is the same person for Kero-chan, Sailor Mercury, and Nakajima Youko? And voice cast for CCS Syaoran, I remember, is also the same for Sumomo from Chobits (Ugh... I'm scared of that persocon...)...
Yeah, I think Sakura's voice cast is a little rusty in the works, too. Maybe it's what Sakura is supposed to be in the serires, but the thing is, there's no emotion expressed... not yet, anyway, we'll see.
If Junko-san is the voice cast for the TRC Tomoyo, I think she'll do well, too. I know Junko- san is good at voice cast for characters who act reserved, quiet, and sad. If you want, you can check out the Rurouni Kenshin OVA. Junko-san did the voice for Kenshin's first wife-Tomoe... it sounds quite chilly.