Social gaming company Zynga (ZNGA) just sent out word that it will be making “a news announcement” via conference call at 3pm. No embargoed details for media folks, with all press materials to be distributed after the call.

This could be all sorts of things: Zynga wants to talk about its secondary share offering. Mark Pincus is stepping down to become Mitt Romney’s running mate. Zynga has hired Sean Payton to launch a New Orleans studio.

But the smart money is that Zynga is going to announce the acquisition of game publisher OMGPop, whose Draw Something recently topped Zynga’s Words with Friends as the top game on Facebook. In other words, if you can’t beat ’em, buy ’em.

TechCrunch reported on Monday that a deal was brewing, likely for around $200 million. This follows rumors I’d heard that various venture capital firms had been offering up unsolicited term sheets at a valuation in excess of $150 million. Any figure in that range is totally workable for Zynga in stock or cash, given that it had more than $1.9 billion in cash available as of December 31.

New York-based OMGpop was founded in 2006 (i.e., one year before Zynga), and has raised over $16 million from firms like Baseline Ventures, Rho Ventures, Spark Capital and Softbank Capital.

This post will be updated once an announcement is made…

Update: Peter Kafka of AllThingsD is now reporting that the deal is done. Also saying it’s for $180 million, plus $30 million in employee retention payouts. No word on if it’s cash or stock.

Update II: Here’s the press release. During conference call, company would not comment on financials. But it did say that OMGPop’s big game would not be renamed Draw Something with Friends…

[cnnmoney-video vid=/video/technology/2012/03/21/an-omgpop-zynga-draw-something.cnnmoney]