They must be pretty confident that the H.264 patents don't apply to WebM at this point; I'm sure Texas Instruments required some assumption of liability on Google's part.
I've never really understood why something as complex a picture encoding/decoding was not thought to be covered by the patents listed at MPEG LA for the H.264/AVC Licensors [1].
It will be interesting to see how this plays out - Either Google goes to war with the patent licensors, and tries to invalidate a lot of the patents that apply to both H.264 as well as VP8, pays them a bucket of money to license their patents, or some other outcome that I can't envision (The patent holders just don't bother going after the distributors of VP8 products?)
http://www.mpegla.com/main/programs/avc/Documents/avcCrossRe...
On the Diary of an H.264 Developer, [1] - the preliminary analysis of Intra Prediction as implemented in VP8 is that "this is a patent time-bomb waiting to happen. " - though there may be prior art to invalidate the H.264 stuff.
We'll see, MPEG-LA has a call for patents on VP8 right now.
"Update: spatial intra prediction apparently dates back to Nokia’s MVC H.26L proposal, from around ~2000. It’s possible that Google believes that this is sufficient prior art to invalidate existing patents — which is not at all unreasonable!"
Which is a bit less worrying than your quote of "patent time-bomb waiting to happen." from two sentences above.
Also, on the number of patents which you number as "hundreds", MPEG-LA only has 164 non-expired patents in the US, about 120 of which can be dismissed out of hand as they apply to techniques or technology that WebM simply doesn't use (e.g. CABAC) which leaves only 44 US patents for Google to dodge, work-around, invalidate or come to an agreement with the owners of.
If they're already paying MPEG LA fees then even if VP8 is found to infringe MPEG LA patents, they are covered.
Most of the companies that would entertain adding VP8 hardware codec already have H264 codec, hence pay the fees.
The companies that don't pay MPEG LA fees, can start paying them.
The important thing to know is MPEG LA sells a bunch of patents. They don't care if they're used in implementing H264 codec or VP8 codec.
MPEG LA fees are relatively low and not a problem for companies like Texas Instruments.
The people who are really affected by those patents are startups, small companies, open-source developers etc.
They get the tech for free, so why not?
More importantly, it keeps MPEG LA in check wrt. to increasing the fees. Monopolies have this tendency.
If VP8 pushes out H264, TI (and others) can just switch to it and save licensing fees.
Even if it doesn't but gains a significant popularity, it'll be a bargaining tool when/if MPEG LA tries to raise H264 licensing fees.
From my perspective?
As someone who might use some sort of video encoding technology in my software, I would rather not pay the licensing fees.
Not to mention that Google innovates with VP8 faster than all of the combined H264 actors (see e.g. the constraint quality encoding mode http://blog.webmproject.org/2011/03/vp8-constrained-quality-...).