Please no.
Although I like the suggestion of helping users to find the right site, a site just to redirect question is a little bit too much I think.
Why?
- Users must be able to find the right site themselves. Often looking for a programming related issue they will come to SO anyway, about their cat to Pets.SE. Or use the StackExchange sites overviewStackExchange sites overview;
- The community effort to redirect all those questions is too much, with no clear gain for those people working their butt off.