I've always liked Asus and their OEM parts for custom builds, and this ultrabook is no exception. Nicely spec'd. Unfortunately, I moved to Apple for the OS, and obviously an Asus won't be running that.
But! Competition is certainly good for Apple, though often I feel as if they don't really care. Consider their iPhone and iPad line as an example. Their specs are often subpar when compared to competitors, but the overall experience is what we pay for, and Apple is excellent at focusing on just that.
The MBA fits this trend too. Will we see Ivy Bridge? Yes. Will we see USB 3.0? Maybe, but it wouldn't surprise me if Apple held out until next year. Will we see 1080p on a 13in MBA? No way. Matte display? Nope, I don't see it coming either (granted, the current screen isn't too glossy, but it's not matte either). The 13in MBA has an SDXC slot, so that's not a big deal. But 512GB SSD? I'm not too sure on that either. You'd think Apple would allow this, but I can't even begin to imagine how much they'd charge for this ($500+?).
Frankly, give me an MBA with Ivy Bridge, better battery life, larger screen with equal footprint (i.e. go into that bezel some), and an HD camera, I'm sold! I doubt I'd spring for the 512GB upgrade, but I know a lot of people would. I survive off of 128GB, but I keep a lot of things on my iMac to supplement that. USB 3.0 is a moot addition for me, as I don't have any devices to take advantage of it (but that's probably circular).
Anywho, Apple is typically stingy with specs, so you can't really compare. The Asus will still run Windows and that's enough to pass no matter what the specs are (for a lot of Apple fans at least). Just wait for it to get Windows 8 *barf*