Great thread and well thought out post. Based on what I have just read I believe you and you wife already have a sound foundation in your relationship.
It would actually be great if she were to read the post as well, if only to open up discussion on this subject for both of you. You seem already to be doing the right steps.
I have a couple of points for you to consider, though this will need further input from others who have more direct experience. A friend of mine, in her forties, had a hysterectomy a over a year ago. She talked of the grieving she went through and the depression she journeyed through while she came to terms with what she felt at the time was a loss of womanhood. She felt less of self. Think, if you will, of men being asked to consider having a vasectomy. Even if they are long past having a desire of becoming a father again, many will run to the hills at the very thought of somehow losing a perceived sense of masculinity. Now ramp that thought up a 1000 times and it may give an indication of how a woman may feel about herself leading up to and after having a hysterectomy. While my friend's physical health problems were addressed with surgery she had not counted on the depression that lasted for 6 months and more.
Next thing - hormonal changes for your wife and how this impacts on her desire for sex. Again this needs more input from those who can speak directly from experience. Think if one day you suddenly realised a food that you once loved just seemed totally bland and unappealing. Every attempt at trying to recapture the memories of savouring the delights only reinforced the thought that this food no longer stimulates you the way it used to. Eventually you would no doubt just find it easier to avoid the food than go through the whole memory and disappointment process. Perhaps that food was always prepared by your wife or mother, you love them dearly but don't want to hurt their feelings by telling them you really now have zero appetite for that food. Enough analogies. Your wife will have experienced a major change in hormone levels. The impact of that can ultimately only be expressed by her.
I strongly suggest that you yourself go to your GP and ask for more information about the impact and changes a hysterectomy may bring. Educate yourself. Become as knowledgeable as possible for a male to be on this area. One day you may be saving your friends' marriages through offering advice on this area. From this gained level of understanding you will be much better positioned to discuss the issue sympathetically than that of a puppy that has lost it's bone. Damn, another analogy slipped in
Another thing struck me as I read your post. You do communicate very well - so I will be blunt - stop with the softly softly approach with your wife. I am most certainly not saying "man up" but be as straight forward as you have been in your writings here. Educate yourself on what she is likely to be going through and then be direct with your communication. First get advice from your GP, next just ask the person who is closest to you who can help you - your wife. I do, though, want to get back on this subject of how you said you have been communicating with your wife lately. I can feel another analogy coming on - hehe - stop being a puppy dog trying to please her all the time. It will become obvious. You will only serve to remind her constantly of the bloody elephant. She may well start taking advantage of your constantly wishing to please and resent you and herself for that development in your relationship. I bet when you first got together you held on to your own "male" space and friends for a long time and no doubt she did the equivalent. Yet you were still attracted enough to each other to get married. Go live your own life a little again - bring some mystery back into the marriage. Go on fishing trips with your male friends, encourage her to do the equivalent. These experiences apart will reward your relationship. It is beautiful that you wish for her every need, don't over do it. She will just see that bloody elephant.
So when you have educated yourself thoroughly on the subject of hormonal changes and the impact of a hysterectomy your communication can then become two-way and not just one-sided as I suspect it may have become. "I want" should be replaced with "tell me how you are feeling - how do we go about his".
There are hormonal replacement therapies that I have been told are very helpful. There has been a great deal of improvement and understanding of these in the last ten years. HRT went through a bad rap for a while but I have been informed that the medical folk have vastly improved things and indeed the safety of using them.
A loving relationship is very precious, you are both already very fortunate to have each other. My best wishes to you both.