They are actually in quite a buying "arms race" in the recent months, with huge deals every few weeks. Its quite obvious that they try to gain as much ground as possible on the develpement of future technologies. I really wonder if these huge amounts of cash they invest will actually pay off in the near future: Facebook just recently paid 19 billion US$ for Whatsapp. The 3 billion US$ Google paid for Nest (a company specialized for internet-compatible termostats and smoke detectors) seems to be quite a bargain compared to - but lets be serious: thats totally insane amounts of money!
So either they expect huge growth rates - perhaps in the scale of another digital revolution - or they simply try to best each other in a huge speculation bubble. Perhaps both actually. Ok, there is a legitime interest in companies which offer exclusively internet services to have products in their portfolio you can actually touch: Its expanding their range dramatically. Just think of the quite-religious-hardware-cult Steve Jobs was able to establish with Apple. Google is trying the same now with their Google-Glasses. The future will show us how this turns out.
For Linden Labs the purchase of Oculus can become a serious drawback in their ambitions of bringing Second Life to a mass-market. I am sure they were speculating of having SL as a avant-garde-product in the new virtual reality-hype, which is now quite doubtful.
Will Facebook continue supporting platforms like SL at or are they focusing on exploiting the Oculus Rift for their own products only? Perhaps with their own virtual world? A kind of Facebook 3D? Or will they even buy LL next?
Another big questionmark is simply Facebook's reputation of being the world largest commercial surveilliance company. Or as the Minecraft-creator Markus Persson said via Twitter when learning about Oculus being sold:
"We were in talks about maybe bringing a version of Minecraft to Oculus. I just cancelled that deal. Facebook creeps me out."
Things to come in 2014 (background info to Oculus Rift)
High Fidelity appendix (more on VR)
LL's new CEO Introduces himself