If it's good DSL like mine is (reliable, and 1.5mbps down 768kbps up, it's reasonable) you should do fine. I have heard that cable has a habit of throttling people from time to time, and one of my co-workers was complaining about how her cable internet was starting to get slow from all the people signing on. My DSL is always as fast as it can be.

As for Wi Fi for regular surfing you aren't going to notice if you're going through the air or directly connected to the router when doing internet things. Both of our Macbooks pretty much exclusively wireless and being able to trot about while surfing is very liberating. The only time I'll hook up a cable is if I have to drag a huge file over from one machine to the other, and even then Ill be more likely to use my "iPodNet" instead.