As the title suggests this is all pure speculation until the playtest drops, but I love the idea of a magus with a wizard dedication. Five class feats is a steep price, but provided the magus comes out with two slots per level ending the game with 4 slots per most spell levels by means of a wizard dedication seems like a really nice way of extending your spell strikes and utility casting throughout the day. You still have 5 feats leftover to pick the choicest magus feats (of course the final product might be stuffed to the gills with unique action feats that make it hard to fit everything you want).