What does FPGA "stuck on 256" mean?

[algorithmic]

Since there no longer seems to be a realistic possibility of acquiring ASIC hardware anytime soon, I am investigating the possibility of mining with FPGA. User dogie in a recent post compares drawbacks of FPGA to other options. One of the points mentioned is "Stuck on 256", which I don't understand.  Here's the relevant section from the post:
https://bitcointalk.org/index.php?topic=160221.msg1693753#msg1693753

3) FPGA: Neither.
Good points: High perf per watt.... that's it.
Bad points: 0 resale if bitcoin goes poof, high investment price way above GPUs, large area needed for farms, complicated for farms, highest investment per hash. Stuck on 256. More complicated (in farms) than any other solution. Pretty hard to find used (decent price).

If someone knows what that means would you please explain to this poor newbie?

[Gator-hex]

Bad points:

0 resale if bitcoin goes poof

Wrong FPGAs are used in electronics and science they have a resale value.

high investment price way above GPUs

About twice as expensive, but that's made up by the electricity cost savings you make.

large area needed for farms

Rubbish FPGAs are way smaller than PCs and graphics cards

complicated for farms

I dunno how sticking it in a USB port and installing drivers is any more complicated than a PC graphics card and installing drivers.

Stuck on 256.

He means SHA256, as far as I know only ASICs are stuck with what they're made to do, FPGAs are re-programmable.

Pretty hard to find used (decent price).

That's because they are good at what they do!

[algorithmic]

He means SHA256, as far as I know only ASICs are stuck with what they're made to do, FPGAs are re-programmable.

Oh that might be it. I wasn't aware of any discussion about changing from SHA256 to SHA512. Seems like a very remote possibility, but even so as you say that should be an advantage for FPGA over ASIC.

Thank you for the input on the other points as well.

[mokahless]

Gator-hex, thank you for saving me some typing.

Listen to Gator-hex.

Mind if I repost this as a quote in that thread?

[ibite]

ASICs could not even be used to calculate regular SHA256 so they couldn't be used for other cryptographic purposes. They are stuck on bitcoin mining.

FPGA on the other side have a real value outside of bitcoin mining (password cracking, etc).