Med2 Preview Event... the answers

[Soulflame]

They weren't sure about specs yet, so what you would need for lagless 4 vs 4 is uncertain (I actually did specifically ask for specs for 4vs4 since it was one of the questions I had listed)
Server stability is something that they probably don't know, since that depends on who does the server and stuff like that. Probably done in Australia, if at all, my guess it that that's probably outsourced to Gamespy.
Lobby improved, I don't know, that's something I might have asked, but didn't occur to me. I'm sorry, I'll try to put that in the list of questions still to be answered that I'll send either tomorrow/monday. Not sure if they know the answer.

Cavalry is still effective, but it depends on what type you have, the enemy and positioning. To me it felt pretty much the same as Rome (barring in mind the kill rate and speed reduction).
If you can get the cavalry bogged down, yes, they will die fast. So their role might be a bit more pronounced as shock troops, but it's hard to say since I only saw very few cavalry units and I didn't examine all of them closely to see how good they were in terms of how much defense, attack, where in the technology tree and how good the enemy was.
But my cavalry didn't die that fast, and neither did the enemies (although the Arquebusiers were pretty nice against them).