Next, they're going to iPhone the Mac
If you look at these numbers - which were just incredible for a non-holiday quarter - the one thing that stands out (as many have already noted) is just how much Apple depends on iPhone revenue. They really, really need another product to spread out their base a little more, and the iPad doesn't look like it's going to be that product anytime soon. They control a large percent of the tablet market - an even larger percent of the "not-junk" tablet market - and it's still only good for around 10% of their revenues. Maybe Apple can get the enterprise to adopt the iPad more than it already has, but I doubt that's going to carry them past 15%. The enterprise just doesn't have enormous demand for content consumption devices.
However, Apple only has something like 10-15% of the personal computer market, so there's tremendous room for growth there. They've been squatting on the high-end of that market for years now, but I think there's an opportunity for them to release machines that are still distinctly superior to their competitors in the space, but at more reasonable prices. I think if Apple could shave 25-30% off the price of their systems they'd pick up another 10-15% of market share, making them easily the dominant PC manufacturer and ultimately adding billions to the bottom line each year. I also think it would dramatically expand their position in the enterprise, which in turn would help the position of the iPhone and iPad in the enterprise.
I'd watch over the next 12 months to see if Apple moves toward making the Mac cheaper and more appliance-like. The new Mac Book might be the (high-end) example of the type of systems that are going to come from Apple going forward. At $1,300 that's not going to light the world on fire, but similar machines going for $800 a year from now would certainly attract a lot of interest and are not outside the realm of possibility. Likewise, with the iMac I think there's room to drop the price without scaling back the capabilities, and that would certainly buy Apple marketshare in the home.