Unfortunately, I followed Apple's and Macworld's advice and launched Migration Assist on my old mac, after installing the Snow Leopard to Lion Migration Assist update first.
I let the process go overnight, and it hung up, getting nowhere. Several calls to Apple for support, and they suggested doing it as Target Mode migration, which is the way I was accustomed. For some reason, it seems that they decided to dumb-down the instructions, because Target Mode was confusing some people.
But it works, and works faster.
I have ten more macs to move over to Lion at some point. They will all be done Target Mode.