I've been running Hardy as I had kernel compatibility problems with Intrepid.
I updated through the update manager, and although slow, the speed did pick up in the early hours of this morning - I guess the servers were very busy last night,
I had issues with viewing videos on YouTube, but I went into Synaptic, searched 'Flash', and re-installed all marked results. This has sorted out YouTube, but some other Flash based sites are still not working properly.
In the whole scheme of things this is hardly a major problem, and Jaunty looks really good so far.