So the sense of this I am getting, is that Xara management believe the most profit can be derived from serving corporate needs, and there is not enough profit for them to cater for an on-line version or tablet based version capable of reading desktop files?

While I take your point of tablet design being niche, I think it worth pointing out that Adobe, among others, have acknowledged the mobile market and are gradually starting to equip that workspace. As tablets continue to get faster, with more storage, it will not be long before anything that can be done on the desktop can also be done on a tablet. The one caveat being that mouse support really needs to be introduced.