Hi Matt
Thanks for the posting regarding the LT-H90LAN. The news story actually states it supports only Xvid rather than DivX aswell. I have checked this morning with the press department for Buffalo Tech and they have confirmed it does indeed support this format, despite the fact that it is not listed on the product's technical specs of the company's own website (why this is omitted I have no idea).
Therefore, your 500+ Xvid videos will be compatible with the H90LAN if you do wish to upgrade.
Hope it helps.
Duncan