You can access your Windows partition and some Windows apps will work if you install WINE. But the software that comes with the OS is good enough for most things, I find. I haven't had any problems, and I switched after using Win 7 on the same laptop for 6 months or so. It really depends on how many programs are essential to you. For me, it's just Chrome Browser, VLC Player, Skype, GTalk, Picasa, Filezilla FTP and Dropbox.
Most of what I do is in the browser as I use Google Docs as my primary office suite, Seesmic Web for Twitter etc.....and I have about 10 Chrome extensions installed for various things.
I'd say try it out but keep your Windows install so you can dualboot....that's what I've done. For the first couple months, I switched back and forth while I got used to Linux..... but at this point I haven't booted my Windows partition in over 2 months.