I find it hilarious that out of the seven applications you put in your list over "app's that wont run on OS X" four is Microsoft productsThat would be like saying "I don't want to use Windows OS because iMovie, iPhoto, iWeb or any of the other Apple programs wont run on it"
I give you right on MS Access, there's OS X alternatives that will give you the same functionality but if you must open a MS Access file your bound to the MS application in question. On the other hand, if you need to open a Bento db, your out of luck if Windows is your OS... same, same...just the opposite...
But I would question any one who says there isn't a OS X equivalent of any given Windows application! You just need to google more...
Let me add one application to that list.. AutoCAD. This product pretty much has a stranglehold on the niche it operates in, and is Windows only. It is absolutely critical to a good number of subsets of Engineers and Engineering students, and a great thing to learn or get trained in if you're looking for a trade without going to college and getting a Bachelor's degree. (You don't need to go to college to be a draftsman, but you do need experience/training in this field and with AutoCAD)
That being said, if whatever app you want doesn't run on OS X, get VMWare Fusion and a Windows license and virtualize it, or run boot camp if you want Windows to utilize all your computer's resources at that time. If you don't want to shell out money for Windows, get the Windows 7 RC1, I think it will work until March 2010. You should have saved enough money by that time to get it.
Dave