I'm actually really happy about this news (no jokes).
The rift has always been an amazing concept that has been implemented really well by some very clever people. However, it was trying to claw its way out of chicken/egg conundrum where the mainstream audience want a large volume of high quality content before they buy a new platform and the game developers want a large number of customers who already own the device so they know its worth developing AAA content for it.
Before, oculus were counting on the enthusiasm of game developers (coupled with the release of their dev kits) to get content for the oculus so it could hit the ground running. However, due to the uncertainty of its mainstream success very few big-name developers or publishers were committing to developing AAA games specifically for the platform.
However, now that oculus is with facebook (and we take Zuckerberg and Luckey at their words) they have the financial clout to commission AAA games to be made specifically for VR. If this does happen and games publishers see the rift as a viable mainstream platform then many more games (and other experiences) will be coming to VR much faster than would have otherwise been the case.
This.
Also, the FB money will ensure that Oculus VR get to release further versions of the hardware even if the first iteration isn't profitable. As a start-up, they were always vulnerable to market volatility with regards to new product types. They now have the clout of the Facebook marketing machine behind them as well as lots of funding.
This is a win IMO.
Can't wait for my DK2 to turn up.