After letting this run for a few days here are my thoughts, in summary.
Verdict: DMM Persistent requires careful DM management but is only absolutely banned in about half of games.
60 people (48%) ban DMM Persistent outright. A lot of these folks weighed in with comments ranging from "I think its broken, theoretically," to "It was broken in my campaign" to "I don't use DMM or Persistent spell, and definitely not both together." From my observation, it seemed that there were relatively few "horror stories" about how a CoDzilla totally smashed a campaign, and more pre-emptive bannings based on theoretical logic.
An area of further polling for the future could be seeing how folks that use different rule sets treat DMM Persistent. For example, the folks that are core-only probably ban it. What about the folks that allow Core+Complete? Or Core+Complete+Races Of...? Or Anything WOTC goes? Or anything 3rd Party + WOTC goes?
On the other far end of the spectrum, 13 votes (~10%) think DMM Persistent is fine under any circumstances.
The majority of folks that allow DMM Persistent put some sort of caveat on it (~29% + 7% for "other"). They either restrict the most abusive tactics (Nightsticks are a big one) or impose some sort of house rule. A common one limits the spells that can be persisted to the highest spell that could normally be affected. Some impose RP penalties or specifically start to adopt countering techniques (more undead, more Dispels, fewer encounters/day).
Finally, a small minority (~5.5%) indicated that they were "not sure" or unfamiliar with the combination. This seems to indicate that most folks are familiar with the combination and know how to treat it in a rules sense, and that most folks also agree that it is technically legal in a strictly BtB sense.
Interesting, thanks for all the thoughts! I think the bottom line is that the DMM Persistent cleric is still a "standard" build -- fewer than half of the DMs out there based on our sample outright ban it. However, you should be prepared for some nerfage, as a player.