Several AD&D/Old D&D fans worked on converting the old "classical" modules to D20/D&D 3.5E; such conversion was of the technical statistics (creatures, traps and NPCs) only, requiring the use of the old module itself for texts, descriptions and all non-rule dependant material, so that the conversion was (almost?) completely legal, especially with an agreement from WoTC about this being done. You can see their work here.

So I was thinking - could this be done for SR4 as well? Can we convert the rules, Matrixes and statistics of our favorite old modules (such as Double Exposure, Missing blood or Mercurial) to SR4?

I don't see why not...

Since no information is copied really (except character names and minor information) there shouldn't be any legal problems with it, I think.

A good thing about that would be an expansion of our pool of contacts, NPCs and Grunts, though some important personalities might have changed through the years... If they're still alive; if you use them "right out of the box", you will still have to replace some gear and skills (especially decks).

Which is not a particularly big deal. Tricked Out Commlink=Tricked Out Deck, after all.

Converting spell lists... converting program lists...

Most adventures use main book spells and programs, and many of these are in SR4; the rest will be converted.

EDIT: Do you prefer the pregen "standard" PCs of the various SR1/SR2 adventures (SR3 didn't have them, IIRC) to be directly converted to SR4 (which means they will be less adapted to SR4, even if decks are converted to commlinks, but more faithful to the original) or to be re-generated using SR4 chargen rules according to their flavor and personality/history/roleplaying guidelines nd while maintaining their capabilities or an equivalent?

First run, and specially food war, could be a good start