This technology could make its way into Xara. For several reasons.

1. Part or all of this technology from my understanding is open and usable. You don't have to use the online tool to take advantage of it. There's a standalone gui at google code.
http://code.google.com/p/seam-carving-gui/

2. Theres also a gimp plugin and I've used it. It's called liquid rescale It works well.
Gimp plugin link "Liquid Rescale"
http://registry.gimp.org/taxonomy/term/178

I think though that Adobe PS CS4 probably has a speed advantage, though I haven't used it yet. I'd bet they would work to speed it up faster than these free tools. It's fun to use it. I'm looking forward to when I need to use it. So far it's just been horsing around, but next graphical banner I have to make, I'll probably employ seam carving.