I'm generally pretty lazy when it comes to moving out of primary. I would say *at least* a month, and hopefully until you start to see the yeast clearing. I often leave mead in primary for 3-4 months, occasionally even bottle from primary if it clears enough. The whole autolysis thing is pretty much not a real issue for homebrewers...
Out of curiosity, what yeast strain are you using?
Packaged: Pearl Amarillo SMaSH, A bunch of random stuff...
Recent Meads: Mead Day '11 Ginger Metheglin, Mead Day '12 Traditional (orange blossom) Mead, Fresh Simple Cyser '12
Primary: Graff, Simple Cyser, Basic Spiced Cider
Secondary: Why do I keep this line here...?
Bulk Aging: Cocobochet
Planned: Heady Topper Clone! Wild Cider?, Hop Metheglin #3 (NZ hops), Trad. Gesho T'ej