Matt Kloskowski posted a commentary about LR, storage space, and big catalogs. The issue of large catalogs in LR and a gazillion photos spread over stacks of DVDs and BRs or possibly several external harddrives is a problem many of us face. Many of us face it with Photoshop, too. Do you keep everything and have more and more to try and keep organized? Do you "show discipline" as Matt suggests and throw away many shots that have one or more problems? No easy answer. If I threw away many of my shots from even a few years ago, I'd have thrown away some photos for my portfolio that later versions of LR or Photoshop can resurrect.

http://lightroomkillertips.com/2010/lightroom-storage-space-and-big-catalogs