The current immigration reform proposal does not provide green card until 10 years after legalization which is 5 years for farm worker. It will legalize almost everyone so people will be able to go back and forth. I am not sure about spousal benefits. You will probably not be able to bring your wife and kids here right away.
I do agree that it seems very likely that it is going to go through this time unlike in the past. But you never know.
If you can I think it is worth waiting for it. If you leave now i dont think you will be able to come back any time soon.