Chrome OS will probably have it's own event soon.
I don't think they're gonna launch it at Google I/O. They're going to launch either in February or March. A Chromebook will have also have it's own SuperBowl commercial. Chances are the announcement will be featured online because no one has been invited to an event from Google. Now the reasoning for this speculation is because of the long awaited touchscreen Chromebook that has been rumored since December 26th. I think Google wants to also brag how many Chromebooks have been sold and distributed world wide, like Andy Rubin usually does on Twitter and Google Plus.
Also the Samsung Chromebook has been out of stock from the Playstore for all of January since and a little before Christmas. Also that specific Chromebook in the Playstore has changed from "OUT OF STOCK" to "TEMPORARILY OUT OF STOCK." So what I'm trying to get to is that all of snippets of information may lead up to a possible product launch or event soon.
By the way, doesn't Google usually show off their new statue before and after an event?
Gingerbread Statue - shown in October 2010, OS announced in Dec 6th 2010 .
Jelly Bean Statue - Same day as the event
Honeycomb Statue - 2 or 3 weeks after the event
Ice Cream Sandwich - Was going to be same day/week of the event but the event was pushed back
I think the prior releases of the statue and launch days of Android before Gingerbread are irrelevant. But, I think an event this month is more than likely due to the fact the last two releases have kinda shown indication of consistency.