BFL, Inaba, hugs and kisses to both of you.
But Please.
Do not you dare test a difficulty changing amount of hashing power on mainnet.
THIS IS WHAT TEST NET IS FOR.
USE IT.
+1 or if you must.... the 1T units consider contacting the recipient of those units and use their credentials for that 24hr period
However...
If we tested on testnet, it would make testnet useless, since it would spike the difficulty to unmanagable levels.
Regardless, we aren't testing any ASIC equipment on the live network either now or in the past, so it's pretty immaterial. We already have a plan, which I explained to several people at the Bitcoin conference on how we are going to handle the live testing when that time comes.