Nickgoa, I think it depends on how you will be bringing the car to Europe. If you're military/diplomat/international organization, you shouldn't have a problem with getting the car serviced (esp if you're being posted to a country where there are lots of other US-spec BMWs). But, your BMW NA warranty won't be valid in Europe (it works the other way around though: if you purchase a US-spec car in Europe from BMW, you get 2-years warranty, unlimited miles--and if you return the car to the US within the four years of the US warranty, and less than 50K miles, you get the balance of that warranty). Your US maintenance program likewise won't transfer here.
If you are importing the car privately into a European country, you may run into more issues: first you should check to see whether you will be able to register it in-country (and what if any modifications you will need to make to it). Also, you should check with the BMW dealer network in the country to find out whether they will service it--and be prepared for conflicting answers (here in France, BMW France has a policy that they will not allow their dealiers to service a BMW sold for the non-Europe market, unless they are registered as a diplomatic/military vehicle, or European delivery). So you would have to go to an independent shop for any work. Best bet with this scenario is to try to find someone else in the same country with a US-spec car and find out what they had to do.
In either case, as you noted from the discussion, RTTI, Assist, Telematic etc won't work, although if you have a 2007, RTTI may be okay. Similarly depending on model year, radio may or may not be adjustable to European frequencies.
As an aside, I would fit new tires on the car (or ship a set with your household goods) if you cannot buy duty-free here. Similarly I'd ship service parts you may need during your time here as well, as parts are much more expensive in Europe. And I would try to take advantage of all possible BMW services covered under the BMW NA package and have the car checked for warranty work.
Hope this helps, feel free to PM if you need more info. There are quite a few owners of US-spec cars in Europe on this board.