There's a new over-the-air DVR going in sale in the spring of 2012.
Called the Simple.tv DVR
What we know so far:
Screen shots of Simple.tv's HTML5 app in action can be viewed here:
A first look at Simple.tv’s HTML5 app — Online Video News
Called the Simple.tv DVR

What we know so far:
[*=left]Single-tuner DVR with full 1080p HD video streaming
[*=left]Stack DVRs to add more tuners
[*=left]$149 price tag
[*=left]$5 month to use DVR service
Screen shots of Simple.tv's HTML5 app in action can be viewed here:
A first look at Simple.tv’s HTML5 app — Online Video News