I think the D5000 is the new low end. Like the previous models, it's stripped down, virtually no buttons to controls things like ISO,WB or other commonly adjusted settings just like the two D40's and D60. No motor drive for older AF lenses. It can't be much more entry level than that.
The price is higher because it does offer more than the gen 1 entry levels offered and you can still find them if you want to. The price is too close to the D90's for sure but I think Nikon planned it this way. if there is something else in the works (and I think there is), they're going to try to get as much as they can before they have to reduce the price. This sort of happened with the D40. Granted it wasn't as much but as soon as the D40x came out it's price dropped.
This is the new standard. It's a good thing IMO. It means that the standard for higher ends models will have to be raised at some point as well. Nikon and Canon both raised the bar on entry level cameras and this D5000 is designed to compete directly with the T1i.
Overall, I think the price of the D5000 will come down. Perhaps also another entry level may or may not be released. I think the reason why Nikon and Canon had so many entry level DSLR's before is because that line was introduced in the DSLR market right as the technology was changing and new features could be added so each company released a "new" model with the added technology in it. I think in the future, you won't see as many in this line. It will be restricted to one or two just like the other lines.