Is this really SNESticle?

There is really only one person who can answer that (and no, it's not me!). That said, I think signs point to "yes". The alternative, that Sardu slapped a copyright notice with his own name onto someone else's code, just seems unlikely.

Fight Night Round 2 is 16 years old, surely this has already been done!

Not a question, but yes, I keep thinking the same thing, and I keep searching, and I keep finding nothing.

Is this legal?

Of course, but all I can provide are the scripts and patches to build a SNESticle ISO from a Fight Night Round 2 ISO. You have to provide the Fight Night Round 2 ISO and any SNES ROMS you want to try yourself.

Why would I use this when Snes9x is already ported to the Gamecube?

What a silly question. This is SNESticle!

So is SNESticle any good?

In short, yes. But it's important to remember that whatever SNESticle is or was, the binary included in Fight Night really had only one purpose: to run Super Punch-Out. It has most likely not been tested with a lot of other games, and it's accuracy and performance is not necessarily indicative of the quality of the PC version of SNESticle (if such a thing ever existed).

It's also difficult to judge its performance since it is running on a 486 MHz PPC which is leaps and bounds beyond anything we had at home back in 1997. (Though, knowing Sardu, it's probably really fast.)

What does Sardu think of this?

No idea. He's probably too busy writing awesome code to care.