Yes send it in. I had my dec 06 60g BD crap out and I sent it in. 90 days is just standard policy I would think and I think Sony has a little more faith in it lasting longer even with the short 90 day warranty. One year later and mine has zero issues, although I have a noisy fan I didn't before.
Someone said it before in one of these forums and although the price IMO is a bit prohibitive for most to do, he said look at the PS3 or 360 like a pc and if it fails get another. Nice to have money huh?