New bit of news recently posted on the Eve online forums:
A long overdue and much needed change will be put in place with the Wednesday, 15 October 2008 patch. Ghost Training, the continuous skill gain on accounts in an inactive or expired state - will no longer function after Wednesday, 15 October 2008. This practice upsets the balance of the game, and capsuleers who actively put their time and energy into working on their characters will no longer be unfairly affected by those few who have not.
Luckily I've never really benefitted from this, as I only managed to gain a few days worth of skill training from doing battlecruisers 3 to 4 when I last quit Eve, I do constantly kick myself that I didn't keep up with the extra 15 million skill points I would have expected to earn during my year off if I kept on popping on and off every 2 months or so as I set the longer skills training.