And welcome another Apple to the game! *IF* Chrome and Firefox came to the Windows Store, they would basically have to be IE wrappers, just like they are Safari wrappers in the Apple Store. Seeing as Windows RT is still not that popular (and without these
guys on their platform, it probably will remain unpopular), these guys have no incentive to produce these wrapper-browsers for RT... just like many other popular apps haven't created an RT version, like Amazon Video and Gmail, etc.
I guess we'll have to jailbreak our RT devices just like people have to jailbreak their iOS devices, so we can actually have some options in the software we run on the devices we
purchased. I happen to be one of the ones that paid the original, $700 pricetag for my Surface RT, and I'm very disappointed that third party developers have been so limited in the RT apps they can produce and that I can install on the hardware I now
own, not license or lease. (Not without hacking my device, anyhow.)
Just as I regret that I chose iPhone, I regret when I chose Surface (along with the fact that I can't access hover features in IE11 via touch -- I
have to use a mouse). Next time I'll probably go Android across the board!