Checking Consumer Reports, Hyundai is still a notch below Honda and Toyota on the reliability front, but right on their heels. They have interesting products and they are on a roll as far as increasing brand awareness, so they are probably the most serious threat to Honda and Toyota right now. However, I think Ford is really the company to watch. They are coming from behind, and are making the right moves at the right time. Adding great small cars in a down economy is perfect, and they saved big development dough by not creating separate lines for Yurp and NA.
In terms of mass appeal products, there has never been more competition. But, in terms of enthusiast machines, some makers (Honda, Toyota notably) have stepped away, leaving car-nuts wanting. That said, if you're in the upper end of the market, the dollar/hp ratio has also never been better. 500hp and more for ~$100K? Really? A $100K Nissan that runs with, or trounces, the best that the Yuros can bring? Geez.