While we are all still trying to figure out what Microsoft is going to announce today, the Bing Facebook page has posted up a small teaser that would indicate that they are involved in the announcement.
You can see the image above and the text from the post says " Big things are coming to Bing tomorrow. You excited?!" which is an obvious hint that Bing is related to the big annoucnement today by Microsoft.
The image talks about the Summer being the "Summer of Doing", but does not offer any insight as to how this ties back to Bing other than "Bing is for doing" tagline the search engine has been promoting. It's another small nugget of information as we try to piece together Microsoft's big announcement and stick around as we will be at the announcement later today.
Thanks for the tip Omen1393
Source: Bing Facebook