sony canon nikon

hello all I have a Sony Alpha a100, and various full frame Minolta lenses: Min 24-85 f3.5-4.5, Min 50mm f1.7, Sigma 70-210 f2.8, Sigma 18mm f3.5 The body is getting fairly tired and I'm itching to upgrade to something modern. I"m nervous that Sony don't seem very committed to the Amount, but...