For those interested in the matter, I've reviewed the Unity threads as well.
Here they face some good arguments but also very poor ones from both sides. They don't technically close any door but the only thing we hear is "it's not a priority, so we'll see later" - there's no real technical discussion with the actual developers, which is bad. Just money talk.
Here the discussion just ends in the void; the arguments are badly ignored IMO. Most people don't know what they're talking about.
Here some guy attempts to hack it through wine. At first doesn't get the support he expected, then people started to brainstorm a bit, but he was obviously the only one interested. Fell into the void.
Here is the most recent discussion (a few days back); nothing has changed, but there's less tension. Much like a bump.
In the meantime, the vote for the Linux support is still the top idea at the time of this writing. If you have five seconds to give away, your vote could count, by the way.
The last thread points to this article which is a good reading with several good arguments.
I'm not angry at the Unity developers, what they claim is very fair and they seem open to hear some numbers and such. However, they explicitely stated "Remember, we're a business that's here for profit" so we can say they want a ready-to-go and already interested large enough userbase so they can go riskfree in this path if it's ever considered - they're not willing to generate interest for Linux users. Which is sad, as many have stated in many other words.
If you read the threads, there's an argument I can't stand which says "There's just too many flavors of Linux, it's too much work to support them all". That is utter crap. What does mean distribution to those claiming such things? The point is you don't have to worry about packaging the way users like it, there's already thousands of people willing to do it for you, and for free; you just have to give them the license to do it, and I'm sure they'll be kind enough to let you review their work for you to see if it fits in your quality standards.
And even if no developer wants to cooperate with distros, they can distribute their own package in a self-extracting installer, exactly like those we find on Windows; what's so mysterious about it? There's only one Linux one should care about.
Another poor argument is the support costs involved. Apparently, Linux users are known to whine more than others because their platform is poorly supported. Well, if somebody's willing to do a bad port to Linux he would have at least tried and the infamous Linux gurus will be there to help, I doubt users will complain more about a buggy game than about the absence of the said game.
Again, there's no anger towards the Unity dudes, those (imo) flawed arguments were coming from users; I just find it sad they're not willing to help. It's their choice.
Also, I only stated arguments I wanted to refute for those who wanted to read the threads; there are many others for and against the idea that are perfectly valid in these discussions. I just won't sum it all up, see for yourself, make your opinion, and eventually.. show your interest.