A lot of discussion is going on around the blogosphere right now about whether Twitter may not be around much longer, because they have not yet implemented a business plan and have no immediate plan for enabling access to the "firehose" of data. It's a valid concern - yet at the same time, it's beginning to go "mainstream", with the adoption of sites like CNN.com and by pop figures like Britney Spears, people and businesses are really beginning to rely on this service. Will it have been in vain? I asked on Twitter, "How many of you use Twitter as your sole update source? (e.g. you don't update Facebook with it, you're not on FriendFeed)". Surprisingly, of the responses I received, not one of them used Twitter as their sole update service. Here are the responses I received:@bethevans: Not me. On FriendFeed.