Working here. Have you rebooted your phone?
Rebooted, switched Siri off/on, reset network settings, all the usual "fixes." On Wi-Fi, on 3G. Nothing.
I don't so much mind erratic uptime from beta services; but it's annoying that unless the problem is so widespread it generates a large number of web posts, even news reports, I don't absolutely know the problem is not on my end. Though, reasonably, of course it's not, it's server-side.
My phone was off all day Monday. Maybe that was it. Siri "lost track of me." If that's it, it'll eventually refresh and magically start working again.
Update: I updated to 5.0.1 over the air (OTA), and come to think of it, Siri hasn't worked since right about then. Saw a few notes about people updating to 5.0.1 OTA, then doing full restore from backup by wire via iTunes (which DLs the full 800 MB 5.0.1 iOS update and installs it) and Siri working again from there on out, no problem. I'm going to start that, go for a walk -- taking a while to DL the full as opposed to OTA iOS update -- let it restore, load the iTunes backup I made a couple of minute ago, see what happens.
I'll post back, but I got a solid five dollars says that fixes it. SOME, though I doubt ALL, 5.0.1 OTA updates (possibly future OTA updates, too) whack Siri. Will confirm, though.
Update 2: Confirmed, fixed after full restore followed by reload of full backup made right before restore. Siri working as well or better than ever -- though I had to reteach the system my contact relationships (wife, kids, parents, etc.) and I'm sure some other particulars will have to be retaught; this may have resulted from turning Siri off and on a few times in attempts to get it working. It was almost certainly the 5.0.1 update that caused Siri to stop working for me, and may well have been because I updated OTA instead of by wire via iTunes.
