Sure, ASICs are always going to beat FPGAs and CPUs in power consumption for the same task, but there are also applications where the ability to update the system far outweigh the power requirements.
Interestingly, SDR is being used for the UK's small scale digital radio station trials this year. Off the shelf SDR hardware appears to be performing well enough at a lower cost than bespoke DAB hardware. Again, this fits in with your base station category.
You're right about timing attacks, I have no idea what I was thinking there. Would they be better for power analysis attacks? I guess if we're concerned about that then we'll end up back at ASICs again.
FPGA based design for crypto would have the same timing attack as CPU. It can be worked around the same way it would for a CPU.