“Forget about rivalries with MySpace and LinkedIn,” said Sarah Lacy in BusinessWeek online. Social networking powerhouse Facebook sees itself on “a collision course” with upstart Twitter. Some analysts see Facebook's site redesign, unveiled Wednesday, as a “desperate attempt to mimic Twitter,” but it looks more like a pre-emptive strike to keep Facebook users from defecting.

Well, “if you can’t buy ’em . . . beat ’em?” said Kenneth Corbin in InternetNews.com. Twitter recently rejected a Facebook buyout offer, so it’s probably no coincidence that Facebook is adding “microblogging” flourishes like real-time feed updates and the ability to follow Britney Spears’ and Barack Obama’s every move through newly limitless celebrity profiles.

It’s also smart on Facebook’s part, said GigaOM’s Brendan Gahan in Fortune. But with Twitter’s 752 percent growth last year and new capital, it might be “too little too late” for Facebook to avoid a showdown with the Twitter juggernaut, and the two sites’ eventual showdown.

Count me unimpressed, said Leonard Pitts in The Miami Herald. I can see how Twitter’s “advance (?) in interpersonal communication” would be popular with young people, who have “the attention span of a squirrel on cocaine.” But its popularity among members of Congress and the news media is baffling. No one’s minutiae is that interesting. (Watch the Daily Show’s take on Twittermania)