As a recovered alcoholic myself, the hair on my arm stands up when I read what SO's go through during the process of a spouse attempting sobriety. I remember how difficult it was for my family, what they went through.
I applaud your wife for seeing that she needed inpatient treatment as i see that as a very positive sign. Many individuals are legislated to treatment or given ultimatums by families. In my opinion, I think the success rate for those who enter treatment by their own analysis have a greater success rate in staying sober. I also applaud you for supporting your wife and making plans for your own recovery.
I made the decision to enter inpatient rehab about 4 years ago and haven't had a drop of alcohol since and have no desire to ever touch it again. I'm done and done for good, that I know.
My experience in rehab. was a good one. I believe that if one can put themselves into full gear while there and avail of all the help that is offered, it can be a very positive experience, much like everything in life.
What to expect? Take it one day at a time for yourself and your wife's recovery. There is alot going on in both your lives right now, bringing about changes, so keep it simple. Go with the flow, don't expect perfection on either of your parts. Visit on family nights and remember that there is help and guidance and support for you too. No one knows how to handle these situations at the start. You will both find your way as time goes by.
Hope this little bit helps and wishing you all well.