Are the days of the entry level DSLR numbered?
As I was writing this, Rocky beat me to it with his post. At the risk of being redundant: No one can give a definitive answer, but here are a few things to consider.
Entry level DSLR's are a huge profit center for camera manufacturers. They not only provide the core revenues that allow manufacturers to invest in the research, tooling and manufacturing of higher-end models, but they also provide an upgrade path that allows companies like Canon to attract customers with an initial, low-cost offering and then eventually up-sell those same customers with higher-end models.
As the quantity and quality of crop-sensor lenses increase, it becomes less and less likely that manufacturers will ever abandon the APS-C market. There are just too many bodies and lenses already out there to walk away from this market anytime soon. With the introduction last year of the 7D, Canon began offering a professional-grade APS-C sensor camera. Canon and Nikon both now have a continuum of crop-sensor models designed to take their customers from beginner through semi-pro. They are not going to abandon this strategy anytime soon.
Does that mean that eventually technology won't make Single Lens Reflex cameras obsolete? Not necessarily. Everything changes and the pace of change keeps accelerating. Just like your home VCR or your Walkman, the technology will inevitably change and SLRs may become obsolete some day (after all, we are talking about a technology that actually predates photography). But, it isn't going to happen overnight and it certainly isn't going to happen before all the current DSLR models have been replaced many times over.