An alert (and anonymous) reader commented on a previous post about Arduino packaging, letting me know that packaging has been accepted into Debian—both the Java IDE and the underlying compiler toolchain. A big thanks to Phil Hands and Scott Howard for their efforts!
This is a very new package, so patches are still rolling in. The DebianImportFreeze has come and gone, but Scott appears to be on top of things, having just filed a sync request a few hours ago to pull in a few more changes. If he keeps that pace up, he'll make MOTU in no time ;)