Not easily. IEs4Linux is simply a quick and easy way of setting up Wine to run Internet Explorer. Wine then translates Internet Explorer's Windows x86 calls into Linux x86 calls. That's really quite cool, but doesn't help much on non-x86 Maemo devices.

For the N900, you'll need to insert an x86 emulation layer, and at that point, you might fight fewer battles by simply putting Windows on top rather than Wine in a virtual x86 Linux system. Either way, it probably will be "way too slow", but that's not to say you won't earn some geek points for pulling it together.

Windows 95 and Windows 3.1 have been run in emulators on the (much slower than the N900) N8x0 Internet Tablets, but there's still time for you to be the first to boot XP on a Maemo device. There's likely an Engadget mention in that one.