Yes, Nys is also training accordingly; but I can't imagine he's doing so at this very moment.

I'm not an expert by any means, but despite what one would think cross and mbk are very different sports...your average mbk course is twice as long as a cross course, there's more climbing in mbk, the bikes are different and last but not least: unlike mbk, cross is a winter sport. So training is very different too...I presume Nys is working on his general endurance, arms and bike position. His already excellent technique and familiarity with dirt tracks should be a bonus, but there's always an adjustment of course.

I found this on the Rabo site:
http://www.rabobank.nl/bedrijven/sponsorin...en_beijing_2008"But Nys agrees that mbk is a very different sport from cross: 'I'm used to having my hands on the brakes, but in mbk you don't need to do that. The bike is completely different from a cross or road bike. The handlebar is completely straight so you have to grow some serious arm muscles. A cross rider steers with his hands, so it's hard at first. Shifting gears goes a lot slower too, and the climbs are longer so you need to divide your efforts well."
It's harder to compare the sports on a commercial basis: I don't think there's a lot more money to be made in mbk than in cross (more on that later) but mbk is a) much more international and B ) an Olympic sport. Both of which do a lot for sponsorship willingness and overall prestige. The only reason Nys wants to try his hand at mbk is because cross isn't an Olympic sport.
So, the money side...I don't have a very good idea of the money involved in mbk but I found this on the UCI site:
http://www.uci.ch/imgArchive/Publications/...EUR%20-%20E.pdfYou'll see that the prize money for the elite men is about the same in WC races (around 2300€ for the winner), but the worlds land the winner almost twice as much in cross than in mbk!

Also, your average mbk calendar features a LOT less races than that of a crosser. Check reigning world- and olympic champ Julien Absalon's calendar:
http://www.absalon-julien.com/images/Calendrier%202006.xlsThat's about 17-18 races, over an entire season. Now check Nys' calendar:
http://www.svennys.com/2007/index.php?opti...7&Itemid=1644 races!! More than twice as many as a top mbk rider. Can you still find the other thread I posted the prize money for the Superprestige and the GVA trophy? If not I'll dig it up again for you.

Anyway, I think that if we compare the amount of races + the prize money we know of, it's safe to say that cross beats mbk by a fair margin when it comes to financial reward. But in terms of prestige, mbk definitely outranks cross.