Absolutely, 775 is superman's solo 'kingdom come' IMO, very similar concepts but in the issue superman didn't act like wimp and leave humanity, instead he stuck around and kicked the Elite's collective asses while proving a point.
Parasite could be an A list villain if handled right, I mean the guy can take away superman's powers and know his secret ID not to mention that he has this interesting horror film look about him.
While I wasn't a big fan of the Earth-one novels, I did like how they handled the parasite and how interesting of a character he can be when thematically juxtaposed with Kal (ultimate giver vs ultimate taker; never being able to be truly physically close to some one etc....).
A bigger problem that than I think is using two of his big ones, Darkseid and possibly Brainiac, for the JLs. Most of the other guys, Parasite, Metallo - mutated normal guys - mostly feel small potatoes to me. I'd like to see something with the Cadmus Project, the several Kryptonite types, Lana Lang, Bizarro... the idea of Bizarro, damaged Superman clones, rather than the classic Bizarro himself. And the Luthor as President storyline, I think that could be epic and super interesting.
Superman's rogues get a bad rep, yet the core ones likes lex, brainiac and Darkseid are all fantastic! So much so that they can trouble the JL and the DCU as a whole.
I wouldn't mind if they use Darkseid for JL since he's always been a DCU villain as much as he is a superman villain and just because Darkseid ends up in JL doesn't mean that can't keep his personal anamosity with superman subplot.
Brainiac is another case entirely, he's a Superman villain through and through but like I said before I wouldn't mind seeing him in a superman solo and then continue his storyline in the JL, since the JL animated proved that ol' brainy is more than powerful enough to trouble the DCU as a whole.
Cadmus could work quite well in the DCCU, infact they can use a variation of the cadmus arc in JL animated where Brainiac takes over lex and subtly alters his behavior all the while gaining more power by becoming prez and ruining superman's rep in the process.