[citation][nom]ojas[/nom]Agreed, though it's still better than having to buy an entire mac(book) to develop iOS apps. though i guess you could develop for WP 7.8, since it'll be supported by WP8.[/citation]
To speak to your second point, I've heard discouraging things about WP8's backward compatibility, and I doubt there's much point, as a developer, to focus attention on WP7.x (sorry, current WP users; blame Microsoft, not me).
As for your first point, the situation is not that different...I mean, to run the WP8 emulator, you need to have 8GB of RAM and can't run the emulator in a VM Windows 8 install. That means you have to have a computer with Windows 8 running on it. Ideally, it would be a touchscreen computer, too, to make using the emulator easier (and give you the option of doing some Windows 8 development, as well).
So, while I could put an mSATA SSD in my ThinkPad T430 and put my $15 upgrade to Windows 8 on there (leaving Windows 7 on my main drive, thankyouverymuch), it would be far from ideal due to the lack of touch on the device. A more ideal solution (for certain values of the word ideal) would be dropping around a grand on a ThinkPad Twist as a dedicated development machine, which is kind of a gamble, and really isn't that much different than buying a MacBook.