Nothing concrete in the way of evidence or links but lets just say a gut feeling based upon a number of things.
I don't know how it will go down, it could be that he will just walk and sign, but my sense of it based upon things that I have read here and there is that Bosh will go and play with Wade in Miami if leaves the Raptors.
Here are some things that are leading to this sense that this will happen.
1. Bosh has indicated that he wants to play for winner
2. Riley and Wade both have rings and Riley a number of them
3. The Heat have the cap space to sign both
4. Wade has indicated that he would like to stay in Miami but this is probably contingent upon Riley signing another superstar.
5. Wade and Bosh give the Heat a great outside inside combo
6. Wade and Bosh played together on the 2008 U.S.A. Men's Olympic team
7. Bosh's latest tweet which is in Spanish Almuerzamos en la Bodeguita del Medio. Es muy linda aqui.
I could find three of those restaurants one each in Palo Alto, nope he is not there, the other in Havana, doubt that he is there and the third in Miami.
We shall see