...has anyone else noticed or it just my client and/or my blockexplorer cache?

Seems to have been more than 2 hours since anyone in the whole universe solved a block, although the difficulty hasn't changed since yesterday.

It's just you, doood. In case of doubt, you can always check the chart at
http://www.bitcoinmonitor.com/
which shows 10 blocks solved in the last hour.

Well, I don't know what's going on then... they've been 0/unconfirmed for almost 5 hours now.

I've tried restarting with -rescan.

I sent another large transaction 100-ish about 50 minutes ago to test, and it now has 10 confirmations, but the 5-hour old ones are still on 0.

Might be time to start paying transaction fees.