I actually did consider the 1TB option for around 5 min, but I believe it's really too expensive. I'll look around for some kind of virtual storage if I need it to store my virtual machines. That seems to be the most cost-effective solution.
Yes and down the road, when someone starts making them. You can easily change it out yourself. I posted a thread in here from ifixit. It shows the break down. Once you get the cover off its pretty much pull it out and pop the new one in. If you ever installed a ram chip or graphics card before.... it isn't any harder. I think you need a special bit to get the screws off though.