What? No Floppy? No Expansion Slots?
Okay, so there's the omission of a floppy disk drive. But let's get real here: All major software programs come on CD-ROM. What are the people with old, CD-less Macs supposed to do? (Obviously, buy an iMac.)
If you absolutely must have a floppy disk drive, a company called Imation has you covered. Its USB SuperDrive can not only read and write to Mac OS and PC-formatted floppy disks, but it can also read and write to special 120MB disks. This one device, which sells for about $150 (or less, depending on where you shop), can handle your low-capacity disk needs as well as your backup storage needs. And it's color coordinated, so it'll look good beside an iMac.
As for expansion slots, if you need them for high-end multimedia or graphics work, the iMac is definitely not for you. Stick with the Macintosh towers and minitowers. They'll provide the expansion capabilities you need.