Whether or not we need to, it looks like it's happening to us. Zynga is in talks with the screenwriters of Toy Story about an upcoming adaptation. I'm not entirely sure why two of the minds behind one of the most successful original film franchises of the past 20 years need to latch on to the FarmVille name; maybe they're broke like the rest of us and just want to get an easy movie out there for the paychecks, who knows. The adaptation does provide a somewhat unique combination of brand recognizability coupled with a completely clean slate for plot invention. The Facebook game has pretty much zero in the ways of story, so the writers can do whatever they want so long as it's about a cartoon farm.
I guess that's the nice thing about these sorts of adaptations; there's no canon to hold your script to, but you're still going to get people in the theaters automatically. FarmVille isn't the only addictive time-filler that's going to see the film treatment; rumor has it that Angry Birds is also due for a cinematic release. Former Marvel exec David Maisel is working with the game developers at Rovio to translate the touchscreen game to the big screen. That title at least comes equipped with characters, although their only features so far are their expressions and in-game powers of division and explosion. It's a little hard to imagine how a game about knocking buildings over with birds will play out over a feature-length running time, but there's the other edge to that clean slate: it's not always so clear how best to fill it.
There's never really been an objectively good film based on a video game, so I'm skeptical about these two adaptations. Then again, they could be the turning point in a downward trend. We at least know the writers on FarmVille have talent. We'll have to see if they put it to good use.