I think before I get beyond basic brainstorming of a Sci-Fi Hack for Swords & Wizardry, I need to figure out what I want to accomplish. Am I looking for something that covers a broad swath of Sci-Fi genres, or do I want to pick a genre and focus on doing that right.
The truth is, I don't know which way I want to go.
It's kind of like comparing Swords & Wizardry to Crypts & Things. S&W can do any genre of fantasy with some tweaks from the GM and buy in from the players but Crypts & Things focuses on Swords & Sorcery and does it well.
I guess the question is more of "do I aim for a Sci-Fi toolbox that can be used with Swords & Wizardry or do I focus on a specific genre". The toolbox can be picked apart and used piecemeal a lot easier than something genre specific, and that by itself makes it potentially more useful. A genre focused set of rules are easier to use as is. Decisions, decisions...
I'll need to read some Classic Traveller for inspiration. I can certainly see turning some spells into psionic powers. Saving throw for skill would probably be the mechanic, but I see them grouped by profession, and some skills could only be used trained. Damn but these thoughts are bouncing around my head ;)