I use iCloud to sync my podcast subscriptions across multiple devices (Macs, iPhone, Apple TV), and generally, it works: All my feeds and stations appear on all the devices. Also, the play position syncs flawlessly. What doesn't seem to work is the synchronisation of the played/unplayed status*: No matter on which device I play an episode, it never gets marked as played on any other device. It doesn't matter whether I acually play an episode to the end, or just mark it as played by option-clicking the item and selecting Mark as Played.
I'm pretty sure this is a (massive) bug (I've filed a radar, too), but I'd like to know whether (1) everybody has the same problem, and (2), you have found workarounds. I for one use home sharing from my Apple TV and sync manually via USB to my iPhone, but I have to update the played/watched status manually on my Macs.
*Note: For video podcasts, this is the watched/unwatched status, which has the same issue.