When I first heard about the new LFG interface, I thought it was a brilliant idea. But after only two days I've realized at least one reason why it won't be as good as the LFG channel.
You won't get random joiners. With the old channel system, a lot of people were always logged into it keeping an eye out. That made for a lot of "ahh, what the hell why not?" joiners. People that didn't necessarily need the instance, but out of boredom might choose to join anyway. I know more than once after seeing a group "needing 1M" that I broke down and joined to help them fill the group.
Also, often it contributed to a lvl 60 running a lower instance just for the hell of it. With the new system, how often is a bored character going to submit himself as "looking for" a lower level instance? Probably rarely.
The new interface is going to be great for putting together that group that knows exactly what they want. But it's going to hamper those occasions where a group just formed spur of the moment.
Opinions?