I'm pretty sure you can do all those things on a Mac. I know you can get Windows Media Player for Mac (strange but true. Maybe called something else). And RealPlayer for Mac (Runs wonderfully!).
And all the design programs you mentioned are available on the Mac in much the same form, at much the same price. Most design studios prefer the Mac; Adobe and Macromedia consider it their main platform, with Windows running second! And all Macs now ship with PalmPilot Desktop, so you should have no hassles there (unless the Palm uses a PC serial port instead of USB).
If somebody tells you that your mac can't be used for this or that, ignore them. If it is worth doing, the Mac can do it.