Xara has been my tool of choice for all my illustration work within a large corporation for the last 5 years. But I bring things into Adobe CS programs all the time: it's basically a requirement in certain situations and for sharing work. So if you're asking if you could survive with just Xara to replace Photoshop, Illustrator and InDesign in most professional environments with multiple designers, then no. Most of us are still slaves to the machine.

But Xara is hands down the most productive vector program I've ever used, and it's raster tools have improved to the point that I find I'm using Photoshop less and less for quick fixes. If you're doing contract work, and are just delivering end product, then Xara is a fantastic all-in-one tool for a great price. (Though as others have stated, certain cmyk print situations can get tricky. Don't have much experience there myself: all my print stuff eventually ends up in InDesign or the like.)