Most modern computers can boot and load Windows from a CD, so you shouldn't have any setup problems. But I still always include a floppy in the computers I build because it costs basically nothing (maybe 8-10 USD) and can still be useful on certain occaisions. Unless you are building a SFF PC and plan to use the floppy bay for something else (e.g., integrated card reader), I'd recommend including the floppy drive.
I thought the same about floppy drives being useless, untill I needed it on my newest computer, It has a Serial IDE hard drive and appartly The windows XP install disc does not have the driver to see a SATA drive and will only accept 3rd party drivers from a floppy drive! My other computer I needed to install an ATA expantion card for a 160 gigabyte harddrive an agen the drivers for that are on a floppy. if and when either computer needs to be reformated I will need the floppy drive.
For the cost I would include one in any new computer I buy. even if you only need the drive 1 time, this saying still applies, "you don't need it till you need it"
I haven't used a floppy for a while now. I have installed XP and Win2k on SATA without needing special drivers. On some mobos, I needed to play around with the BIOS setup before it would see the SATA drives. Neither of the SATA computers I built have floppy drives.
I agree with raggie about floppies, but it might be easier for most people to have a floppy drive, although it can be added later if necessary.
When I need to boot from something other than the hard drive, I boot from CD. But there's a trick to that. If the software is available as a CD image, I create the bootable CD with Nero. Other CD writer programs can do this also.
If the software isn't available as a CD image, then I put it on a floppy and make a bootable CD using floppy emulation. I don't use a real floppy drive with real floppies though. You can download a virtual floppy drive from the internet. It costs nothing, and it takes up no space inside the computer case. You don't have to open the case to install it, it requires no cables, and you can format it in one second. The only thing you can't do with a virtual floppy is boot from it, but you can make a bootable CD from it.
Get the floppy, it's cheap insurance. You never know when you may need one. Maybe you may not need it for yourself, but if you supply others with PC help, they may still rely on the floppy to transfer data.