I bought a new laptop for my ex about 6 months back, and it had a gaming level graphics card, running a core 2 Duo 2.6Ghz, 64-bit Vista (we will switch this to Windows 7 when it comes out on October 22nd) and 4GB of RAM. DVD-RW, good networking, bluetooth, large hard drive (250GB is large for a laptop) and a decent built in web-cam. It cost US$750 before tax/shipping. Besides a snazzy case, the multitouch trackpad, and the backlit keys, it features darn near all the _HARDWARE_ capabilities you could get in a MacBookPro. Mind you I own a bit older MBP (and dual-boot 10.5 and Windows 7). I'll need to try out the new 3.0 beta BootCamp driver set. There are some tweaked and proprietary devices in Apple's equipment that could work wonderfully in Windows (and linux) if they put in the effort. I applaud that they are getting some of it to work passably, but they could do so much more. I will have to agree that Windows has never been really good for low-latency audio work. They have improved the audio interfaces as far as usability and mixer issues in Windows 7, but I really can't say as I don't do music authoring on a level any farther than amateur, and haven't installed my sequencing software on my Windows 7 RC box, nor the dual-boot section of my MBP. I would be really surprised if they enabled real multi-touch capability with the newer touchpads under Windows 7. Right now the multi-touch is really designed to work for touchscreen style. Still, being able to adapt it to a smaller pad would be nice. I currently do stuff with a Wacom tablet for pen-input things, as I don't have a touchscreenmachine, let alone a multi-touch capable.
Enough with my rambling though. The basic point I have to make is that Windows 7 runs pretty well as-is on Apple hardware, but it could run a lot better given proper support for Apple's proprietary modifications. There are laptops that are cheaper and just as capable hardware-wise as Apple's MB and MBP. They may not be as sexy externally, but they certainly fill all the different portions more than adequately and at a lesser price. For those of us who do have MB/MBP, we would certainly appreciate it if we could get the full usage of the hardware. We almost can, but there are specific, noticeable things lacking. Hopefully this will change.