Hi Peppera-Ann,
What fatbrit said. I'm currently in the US and running later in the day than I usually do - hence the late response.

Basically, it's next to impossible to predict the chances of your getting your visa. What you want to do is to submit the best case you have - and as fatbrit says, the ideal situation for you really would be for him to be back in the UK, making preparations for your arrival by finding a job and looking for a flat. That way the "little issue" of his being illegal in the US becomes moot. If he stays in the US, it looks like he isn't serious about bringing you to the UK.

Ultimately, they can't really refuse a UK national the right to bring his lawful spouse to live with him, but he needs to show that he's able and willing to provide for her. And that's lots easier to "prove" with him in the UK, actively looking for work at a minimum.
Cheers,
Bev