Every group that I've ever heard about that has gone big time into using verbal components for spells has gone off the deep end and just gotten wierd. Granted, its a sample size of only two, but its a sample batting 100%.
I think that using verbal phrases to invoke spells - even the silly Harry Potterish psuedo-Latin ones that are kinda cool - blurs that necessary and important dividing line between the game and reality. If someone shows up to one of my sessions in costume and chanting spells, I'm going to think that they are either off thier meds or need to get on them.
In addition, getting serious about verbal components invariably leads to religious issues. In both cases, the groups I knew about did the obvious thing and went and looked in real world 'magic' and witchcraft books for inspiring source material.* Invariably this either leads to a) someone deciding that Wiccan/Satanism/etc. is cool, 'converting', and that person starts bringing thier religious perferences to the gaming table, or b) someone else in the group deciding that person A has converted a Wiccan/Satanist/etc., that persons A's soul is in mortal danger, and they start bringing thier religious perferances to the gaming table. Regardless of your personal religious stand on this, as a referee I'm sure you will agree that that is real world conflict that you just don't need getting in the way of your attempt to tell a purely fictional story.
So, as an occasional bit of color and humor, (a player casting 'mend' and then exclaiming 'Oculus Repairus'), I'm likely to smile and guffaw at such stuff, but I'd take steps to squash it if I ever thought it was moving beyond an occassionally witty geekism, to being an actual prerequisite for the act of having a character cast a spell.
To say nothing of the fact that if NPC's did it, you'd have the problem of Player 'spellcraft skill points' interfering with the metagame in the same way that player's knowledge of modern technology invariably leaks into character knowledge.
*BTW, real world 'magic' and Wiccan stuff is incredibly corny, pretentious, and ridiculous sounding to me so why you would ever do this I have no idea. On the other hand, if you read Gygax's appendix to the first edition DMG, he basically advices DM's to do exactly that, so maybe that's where it comes from.