Raspberry Pi http://www.raspberrypi.org/ is coming closer to pre-ordering. Looking at the pictures we have a reasonable capable Linux system in a small space with small power consumption and general purpose IO.
In the past hobbyists have experimented with home routers, which can be fiddly to work with and offer limited capabilities. The Raspberry Pi will be cheaper and should have a lot more support and community around it.
It should be possible to make more, quickly, with this kind of system than with a system such as PIC. The possibilities for hobby work, never mind education, are endless.
I’ve just had a look at the FAQs. The GPIO is unbuffered low level TTL (3.3V), so will need an interface board. Very interesting though is that interface buses such as I2C will be available which offers a lot for interfacing external boards. The robotics project I did at university was based on I2C for example! Our robots, back in the 90s, had umbilical cables to the host computer, but a Raspberry Pi could easily allow the robot to carry quite a powerful computer on board.
So it doesn’t look like the end for playing with PICs. The I2C and SPI buses on the Raspberry Pi offer a lot of options for PIC based expansion projects. I wonder how fast it could work, whether it would be able to be used for some heavier digital signal processing work or software defined radio for example.