People really get excited about new games because it offers the promise of "Finally! What I want in a game!". Due to the polish of existing games people want to jump right into the new game and have it run and play like their old game - people expect the Warhammers, Conans and Vanguards of the world to come out and run as smooth as Everquest and WoW and it doesn't happen that way. They also want the Everquest or WoW feel but with the new story-related textures. Granted I think developers, whether through financial issues, "higher up" concerns over development times or other factors do not help by releasing such games in "incomplete" states does not help the issue. Each game had potential to do well and be strong in their niche - however due to the release states of the games they were expected to run a 100-yard dash with their legs tied - some of it by the developers, some by the fans.
I am looking forward to SWTOR. I know a lot of people on this site are (AngryBeaver
might be one of them

) but honestly I don't expect it to be perfect on day one. But if within a couple weeks or a month issues are not addressed - i.e. performance issues such as Vanguard's - then that would be a red flag. Issues like "balance" are never going to be addressed whether it is on a PVE or PVP level. There is no way to do that and every person's idea of "balance" will vary.
Again I do have high hopes for SWTOR but I am also being realistic in that it will do well but have it's naysayers and fanboys. I would honestly like to a see a game do well but be a "WoW Killer". I think the industry and fans realize now that moniker is a deathknell to the usurping game if anything. I think if SWTOR releases with say Warhammer's 300k subs and continues to build I think it will be a success - but to expect say 2 million or 5 million subs off the bat is just asking for a disaster. Bioware is a great company from all reports but that is just a ton of pressure on them and is really not necessary.