I've been working on setting up a private pool for myself and a few friends (combined we're around 25-30 gHash/sec). I got pushpool compiled and running, blkmon running to make sure long polling is active and working properly.
I'm testing it on my cluster of computers (~5 gHash/sec). It's been running a bit over 30 hours now, so on average I would've found something at current difficulty, but I know luck can always screw you over.
My only concern is whether or not pushpool is actually sending/submitting proper work to my GPUs. They're submitting shares and I've run some calculations based on the share database timestamps (share count during time frame * 2^32, divided by time frame in seconds), which is giving an approximate gHash equal to what I've expected.
Extra info edit: About 1 in 200 shares submitted to pushpoold are forwarded to bitcoind, log file returns: PROOF-OF-WORK submitted upstream. Result: false. Not sure if that has any additional meaning.