Do pool servers communicate with bitcoind, and in what capacity?
getwork is for all intents, completely deprecated due to it's inefficiency. At this point a single ASIC device can completely swamp a bitcoind with requests as they're able to exhaust the 32bit nonce in a fraction of a second. The situation is severe enough that pools like BTC Guild have extraordinary large (6%+) fees on clients using getwork in order to get them to switch to more efficient methods. 

Internally, pools like Eloipool use getblocktemplate to generate work for the clients, and then use stratum or getblocktemplate to communicate with the workers depending on the request type they make. getwork is not involved at any stage. In fact, it's currently pegged for complete removal at some point.