Q: Ok I have a quick question, when running KDE can you access ALL your OS X apps?
A: No; because applications in OS X are actually folders and KDE will read them as such

Q: Do they look like the aps on my linux machine?
A: They can, depending on how you setup KDE

Q: Oh and what are the advantages, besides the coolness?
A: Possibly immortality or meet Paul Bellini.
MacBook 2GHz Intel Core 2 Duo w/ 2GB DDR2 RAM & 120GB SATA 5400RPM HDD
Canon Rebel XTI
Google Cr-48 Beta Laptop