I use Vent with my FFXIV LS and FFXI LS. I'm a fan. But I never (or rarely) get into a FFXI PT or a FFXIV behest/guildleve PT and have the group say "Hey log into our vent, lets talk"

Now in FFXI you had to sit through 5-10 auto attacks to use 1 TP move which gave you a lot of time to talk.

In FFXIV as we're all aware have to press a button for every action and thats further compounded when using a gamepad. This will NOT fly for PS3 users in it's current state. Communicating becomes a choice of losing DPS/TP or playing in a world of mutes. Adding in auto attack will allow for players a chance to communicate. It's a big deal that people who don't want AA are downplaying.
having AA in FFXIV won't equal the AA in FFXI simply for the fact that, you will not be waiting 5-10 AA's to use a single TP skill. you will have 1 round of AA and most classes will be able to use a TP ability. FFXIV has a much more robust skill system than FFXI.

Having a AA in FFXIV will do more good than harm for everyone.