There is a tool called LiteStep Theme Downloader - LSTD, which can help a bit.
You can grab it here:
[copy/paste the address to the empty browser page, because offsite links doesn't work on bip.ru :( ]
It works fine with 90% of themes, but there are some troubles:
1) if used modules are defined by e-vars like
instead of IF ... ELSE
Some theme makers are bad, bad, bad ;)
2) or arhive has unrecognized format (actually I don't know why zlib doesn't work with 1984 theme, for example)
this tool won't work
To enable using downloaded modules just add a line
where X:\Download\LiteStep\Modules\ is a path to them.
Also there is a disadvantage: LSTD can download modules only from one place, so sometimes it required for changing the modules archive site from