Is It Good For Gaming
The system is, and I believe most games that can be made to run on Linux can be made to run on OSX.
Do EVERY Software That Worked On W7 Will Work On Mac ?
Is this even barely relevant? does every piece of software that worked on mac work on windows 7? Of course not. they are different operating Systems. Not every windows program created can run on Linux either, but a lot of people choose to use Linux, sometimes for the very reason that they can't run windows software.
And even for those programs that don't run- there are equivalents that can be had that are at least as good, if not better. And, even then- most Windows programs have versions that run on Mac anyway (office, for example).
Re: gaming: gaming hardly counts anyway. if the market share of the mac OS or Linux went up, then game developers would make Apple and Linux versions- the only reason they don't always do that now is because the market penetration of windows as well as the very mindset you illustrate (windows is the only OS that can play games). Besides, the change has already started- now that game developers can create a version for windows, and a single version for both Linux and Mac OSX, more of them are doing so.
A very similar demographic in Operating Systems earlier on had DOS at the forefront- it was only after Windows became more popular and easier to run that game developers switched to create games that ran on Windows. the First quake, for example, was a DOS game, whereas Quake 2 was a windows program (for windows 95). This switch was not because it was too hard to create a game on windows, but rather because the developers had to essentially learn an all new architecture- with DOS games, most of the programmers had learned all sorts of tricks and hacks to get more speed from their games running on DOS. these same techniques couldn't be used on windows, because the architecture was completely different.
As far as I'm concerned, basing an OS choice on "what games can I play" is pretty stupid.
Apple Cant Replace MICROSOFT
And Even If They Want To It Will Take 2-3 Decades
And If They Did How Would Windows Appear
"Apple Windows" -Sheesh What A Name
Replace. Not buy.