Exactly, "Ultimate" they call it, and the Enterprise versions. OEM for 49 euro or something? That's not that a good I think, but you're right, these OEM version, in Germany, bec./of their BGH (hightest court there) travel to another comp - in theory. Since they phone home, I don't know if MS Germany will give you the needed code when they know it's not the original pc anymore. So I wouldn't buy, but buy a regular version for under 50 euro as well, but that travels without problems. Especially Win7 could become highly valued in some years in case even Win9 isn't much better than the 8 flavor.
On the other hand, it's always one Win, one pc, whilst for other sw, those OEM version often don't install but on a single pc, when the ordinary version installs on three, recent example for me, was wondering if to buy Adobe Acrobat 9 OEM or, for the same price, 8 for up to 3 pc's... well, that's probably become a defunct prob for many people now, and at least old Acrobat ebay prices will go down, I suppose.
And then, my posts except the very first here prove that these language settings ain't as important as I once thought since then you can tweak any language a little bit. Ok, not thoroughly: German pops up in my system for dialog boxes and such, so I'd clearly prefer a genuine English Windows.
Btw, for English Windows, the simplest solution (for Continental Europa) is to order them from British vendors: Postage is from 2 to 5 pounds, prices are decent, delay is a week or so - I've bought lots of sw in GB during the last years, never had problems (but bying from the U.S. often means problems: customs (not for customs, but for vat, calculated on the price you pay - they even look at the corresponding ebay page in order to know what you really paid!), delay (up to 1 month is ok, but once, I waited 3 months, had been sure by then the seller was a crock, which he wasnt - after arrival, I verified he had sent the parcel 3 months ago!), transportation cost (often 30 bucks and even more, and some commercial sellers do not even send to Europe), and on my latest try, last year, I got student sw = an "educational" version, for having bought the ordinary version (and paid accordingly) - that's ebay, the trans-Atlantic variety... (After he got my red warning then, he even contacted me he did this (= stealing?) for a living, so I please would I take away the negative score in order to not further harm his business, oh yeah.)
So, buying in GB is always a good idea if the price is right (and it mostly is) - I would have bought there English Windows version, wasn't it for the need to then re-install all your stuff, so I live with German pop-up boxes...
Vistalizator? We all become acquainted with a lot of formerly unknown things here, that's good! But the bad news is, "It still requires you to download the official language packs from Microsoft though." means there's high probability it'll be illegal! (= the download and use of the language packs, I mean, outside of their legitimate use framework) But tell them to do the same for XP (and in a live system, please), and I'll install it, notwithstanding! (Just dreaming.) ;-)