Most people will more likely than not use BitcoinTalk to find out all the (new) information about an altcoin they take an interest in. Unfortunately, BitcoinTalk is becoming a kid’s playground lately and the forums are a bit cluttered. Several altcoin communities end up creating their own forums, which is a good solution to some extent.
Especially when you look at the SysCoin or Darkcoin forums for example, you can see they are buzzing with activity, information and fun. Other coins see a lot of interest at first, when then drops off as more time expires. It is hard to keep users motivated to use an alternative forum for a specific coin compared to just checking the BitcoinTalk thread, where most, if not all information will end up eventually.