It's essential...even if you use it just one time year! Imagine your system crash and your CD-drive don't work and you can't communicate with your hard drives... The only way to boot is with a floppy! It happens sometimes, beleive me! I read an article in the newspaper some time ago which asked the same question as you did and it answered it when its system crashed just as I have answered.
But what when your only bootable zip disk dies on you, and all you have is loads of friends who are all too happy to make you a boot disk....
I'd personally put in a floppy, also some (AV recovery/Partition magic rescue disk/Lost and found/ERD) may need to be booted off a floppy.
I have 2 athlon systems running Win2K w/o floppy drives. If you can boot from a CD, you don't need a floppy....... assuming you can create your own boot CD which will load dos or win98 so that you can do a bios flash.
I couldn't set it up in BIOS, it was SCSI. But I did disable the Floppy interface and set the floppies to none. I would suspect that my SCSI card relecated it to A: except that it also showed up as D:, so I suspect Windows.
Just remember, Windows in safe mode will not work with anything else but a floppy drive and if you have any problems that causes Windows to be unhappy, you will be out of luck.