A friend of mine from USA claimed in IRC last night he is in beta. He said he was mighty disappointed, using the words "SWTOR is a poor single-player game, but with a monthly fee". He claims there is no reason what so ever to group together with other players, and if more than one are on the quest in the group, only the group leader gets to interact during the negotiations (so even if you would want to make different choices during discussions, you just have to accept what ever the group leader chooses). Basically, according to him, it means there are zero groups going on in beta, everybody runs around solo.
I don't know how accurate that description is, but I don't think I'll pre-order this game before I've seen a few proper reviews from people who actually have played the full game a bit.