It *should* be upward-bound, and would be if not for all the skepticism encircling Butterfly Labs and their ASIC products.

If BFL does actually produce their SC line of products, it will mean very scary things for your average every day miner. Even though there are lots of FPGA modules available for purchase from various manufacturers, the "meat" of block creation is still GPU mining. The release of FPGAs didn't impact the viability of GPU mining all that much because the speeds are in the same neighborhood (Overclocked 7970 GPU ~650MH, BFL FPGA Single ~830MH). If BFL releases even 1/10th of the ASIC products that they have pre-orders for, the difficulty will just about double in a mere matter of weeks.

This is all compounded by the fact that the block reward will be cut in half sometime in early December. Enthusiasm for the currency as a whole will be drastically reduced on the miner-side if GPU mining is no longer viable unless you have free electricity, and even then, it won't be nearly as profitable. Who wants to run their cards at high temperatures for next to no reward?

The bottom line is... If ASICs make it out onto the market, you better have one, or you'll be making a fraction of what you're making now with GPUs. I'd rather have tens of thousands of users under 1GH/s mining/trading/spending coins, than a couple hundred users close to or over 1TH/s. Fewer users and less enthusiasm amongst the community means a drop in value.

We all know what happens when the majority of wealth in an economy is limited to the privileged few.