You might be able to recover them with an undelete program, but it's an iffy prospect at best. Assuming you haven't overwritten them, some undelete programs will be able to figure out the type of files left by scanning the entire hard drive for file contents. If the hard drive was fragmented, this probably won't work too well. Otherwise, you might be able to get some files off of there, but you won't know their names or where they were located on the hard drive - merely that it's a Microsoft Word file of X kilobytes in size.
If you lost something irreplaceable, it's worth it. If you just need to redownload stuff, it's probably not worth it.
Problem is that wiping the hard drive erases the FAT table, so the entire directory structure and file names are lost. I don't know if there are any circumstances where you could recover that info. There's a lot of different undelete programs out there.
If it looks like the partition just isn't showing up, it's easier to recover the files...in theory, anyway.
Note that not all problems which are undelete utilities do the same thing, even if they say they do the same thing. Test them first if you can, especially if they have a free demo - it can save you from spending $80 on a program that just can't recover anything in your circumstances.