OH man. You have to do it every so often.. If you don't, Home will corrupt your HDD. You should do it asap. check out this thread I just made http://www.yourplaystationhome.com/f2/how-fix-your-ps3-2279/#post9601
hopper.. i will not exaggerate to you when i say that it used to take me exactly 25 minutes (on a good day) to log onto home before.. but thats when i had the cache on max and havent deleted and reinstalled home after months.. but a simple reinstall and selecting the minimum reserved cache, i log on pretty much instantly.. and ive probably bought almost everything at the mall plus have almost all the rewards. have you tried doing that before a reformat..?