When it comes to South by Southwest, even a blink of an eye can cause you to miss the latest lineup addition. After all, in just the last two days alone, we have uncovered 100 more confirmations from artists and bands currently scheduled to descend on Austin, Texas between March 18 and 22. As a result, our list of confirmed acts for SXSW 2009 now sits at 450.

Among those highlighting the newest crop of confirmed names include Late of the Pier, The Pains of Being Pure at Heart, This Bike is a Pipe Bomb, Opus Dai, Ian Moore, The Whip, Kittens Ablaze, Drew Danburry, The Tiny, and Ryan Gosling’s personal outfit, Dead Man’s Bones.

As for the rumor front, Faces, The Rapture, VHS or Beta, Simian Mobile Disco, and Tiësto remain the hottest names filling the blogosphere as potential acts for 2009.

Of course, even after all this, we still have only unearthed 25% of next year’s lineup and are still quite a ways away from knowing all 1,800 acts that will make up South by Southwest’s 2009 bill. Be sure to check out our recently revamped SXSW Outlook page daily for all the latest new confirmations and rumors.

P.S. Are you an artist or band playing SXSW ’09 and/or interested in playing at one of CoS’ official showcases during the week? Drop us a line with your details.