Yes, it's possible. I've an Acer Aspire One that I bring with me when travelling and it comes with a Radeon 6250 supporting GL4.2 and even some 4.3 extensions. It's not particularly fast - maybe good for up to and including a Quake 3 level of scene complexity - but the full shader/etc capabilities are there.
I don't know what the current state of play is with Intel netbook graphics, but if you can get something with a HD3000/HD4000 you'll have good enough GL3.x capabilities; again without being particularly fast.
In both cases you'll get better D3D support than GL support; particularly with Intel graphics where anything reasonably recent should support D3D10 or 11, but have GL support that's lagging a few versions behind.
In general the main bottleneck on these is going to be your CPU; for programming that's going to affect compile times, program startup times, IDE usage, etc. However, and if you can afford it, replacing the hard disk with an SSD can be a useful investment - not as good as with a more mainstream machine (that CPU bottleneck is just too much) but it does help make general usage a bit more pleasant.