Just to clarify, I've gotten confirmation that the actor being used for Tyrande is the same as was used in WarCraft III (and since). It's also important to note that context for how she sounds is key (or the perception thereof) in relation to the various situations she's in and worth keeping in mind as well.
That said, we are always open to feedback provided that it is kept constructive.
The accent does not seem conducive to the character as she is currently understood by the playerbase, from WC3.
to elaborate, why does she have the troll accent? Things out of context are not often explained easily when the information being requested is something that is intended to be kept a secret. That she has this accent is not so troubling as to the lore; it seems she did this with too much of a troll accent.
Night Elf sound files in game for the various characters and leaders all seem to be a clean, non-troll language. The odd thing is that if Night Elves are going to be made into more troll-like people as a race, what happened to my warrior women of doom from WC3? That's the race I wanted to play as, not an offshoot troll.
Her work as a voice actress is amazing, as evidenced by the range she has displayed when comparing between the two sound file sets (WC3, WoW 4.3 5 mans). My personal issue is as stated; I did not sign on to play a troll, when playing a Night Elf.