Lets face it: there's no real reason why WhatsApp, the super popular proprietary, multii-platform IM system can't come to Windows Phone 7.5 Mango. None. They get their database/contact access, runs in the background, push notifications, fast-app resume--everything they need. And with Microsoft going out of their way to woo developers and services, it's not exactly a stretch to think a WhatsApp client is coming this fall.

So when the official WhatsApp Twitter account tweeted "Did you know that mangoes account for approximately half of all tropical fruits produced worldwide?", it's not hard to read between the lines.

Sure, it could be a coincidence. Perhaps they were feeling irreverent today or their Tweet manager has a thing for mangoes, but c'mon, this was a wink and a nod, especially that BUILD is happening right now.

Update: We should note that Bill Cox (Sr. Director of Communications at Microsoft for the Windows Phone Division) and Joe Belfiore have re-Tweeted the @WhatsApp tweet. So there you go.

Update 2: And look at that. In the media section of WhatsApp's website, they have a new "teaser" image up. What's new there of course is the Windows Phone logo. So lets just consider this open/shut. WhatsApp is nearly here. (Thanks, Plaffo.com, for the tip!)

Thanks, michelloyen and Rob, for the heads up