David Hyatt...
While I'm no expert on this, from what I know, Hyatt is a newcomer to the Cocoa experience. From what I've read, he's a newcomer to Macs in general. His first experience with the Mac was when he decided to learn Cocoa for the intent of making a OS X native version of Mozilla.
Now, couple this with everything else we know:
1-IE sucks on OS X. Apple knows this. MS MBU knows this and has said so publicly (not in those words, though).
2- MS MBU doesn't see IE on the Mac as a huge priority now that the 5 year agreement is over and they derrive no income from it's development.
3-Apple has an "iApp" for just about every other application need (mail, mp3, video, photo) out there - but none for what most people use their Mac for - surfing the web.
4-Chimera is open source. Gecko is open source. From what I understand about this, Apple can do one of the following - a) Use Chimera so long as they make their contributions to it public and accessible, or b) Use the Gecko rending engine and create a new closed source front end on it So long as Apple doesn't modify the Gecko rending engine, the product could remain a closed source project, with Apple controlling it.
Everybody talks about what would happen if MS stopped making Office for the Mac, but the real fear at Apple is over what MS is doing to Apple with the sad state of IE for OS X.