Heh... Beat me to it, you did.
Folks, he's telling you the straight skinny there.
WINE, the library, is true to it's eponymous acronym.
WINE, the environment is NOT true to it's name. It is a framework to fake a Windows application out, thinking it's running against Windows. By definition, a virtual environment, and therefore emulation at several differing levels. Virtual machines like with VMWare or VirtualBox are high-performing emulations- but still emulations all the same. You're not native there, though you're close. The same goes for WINE. You're close in many ways, but you're still not native (Some things run faster under it, and others, nowhere near as fast, if at all...)- and you're at the whims of the vendor of your title as they don't officially support WINE (Except for a few notable exceptions like Eve Online...they just don't...not even Blizzard.) and they can apply a fix to some perceived problem and break your usage of the title under WINE- and then not shed a single tear for you. (Witness what happened with WoW and some of their "bot" prevention measures- if it wasn't for the massive uproar that ensued, they'd have written you off, guys...).
In the end, you're sending a message. You're not interested in Linux gaming- and you're emulating things while doing it.
Heh... I'd rather work with Greenhouse or someone like them than Valve, I know that much. I'm keen on seeing the AAA crowd begin to wise up here, but this stuff's not anywhere near as big a deal as what Wolfire's pulling as a PR stunt with the Humble Indie Bundle deal.
Only in class. Even a Virtualization Environment (the first word should be a BIG hint...) has emulation pieces of hardware edges and WINE does similar things with it's stuff.
Again...WINE the library, you're right on the money; WINE the application loader, you're not being honest by calling it an abstraction layer.