Given the ever increasing file sizes I think we're past the point where that much Flash storage makes sense in a single device. Bring back the mobile hard disks, I say.
I'm kidding. The larger SSD might still be extremely expensive, with 1TD drives costs $2,00 or more, but there are signs that the prices are dropping faster than screen resolution is increasing. Micron unveiled a 1TB SSD at CES 2013. They expect to sell it for around $600, and that means that by the time the iPad had a similar amount of storage the prices will likely drop by half or more.