help! dog suddenly has no interest in me

you have to go back to reinforcing it and slowly fade the reinforcement.  Go to varriable reinforcement scedule and increase the duration between rewards.  You can also slowly make the reward less valuable and less in amount and hope that some cognitave dissonance will happen.  But the rat may never have the same love for the wheel again.  This effect is actually found in humans and is a argument against our current educational system.

my focus is animal learning an reinforcement schedules.  We use rats because they have been so inbreed that there is little genetic difference between the subjects.  They are like clones.  I do little ethology so rat behavior is not my speciality.  Supprisingly enough rats also have similar stress behaviors like dogs.  They itch, sniff, squeek, and deficate. 
By leaveing out the middle part you allow for a unique solution, and possibly a better one.  Also the leader does not always have the attention of everyone in the pack.  Look at dog packs where the leader, barks the most, the other pack members will eventually learn to ignore the alpha's barking if it is meaningless.
 
  If your dog is ignoring you spend some alone time with the dog and build the bond.  Try doing a teem sport like agility, where you have to work as a team.

Wouldn't you agree that taking a dog to doggie daycare, at least once to see how it goes, after fully explaining your concerns to the staff, is a better idea than just not taking your dog because you're afraid that it won't do well?

 
That depends.  There are day care operators who just like dogs and wanted to work with them, and there are day care operators who know a lot about dog behavior.  A neophyte owner who can't diagnose their own dog is unlikely to spot the difference.  I think it's a good idea to take a 1/2 hour private lesson with a trainer to determine whether the dog is appropriate for a group play situation, then ask the trainer for a recommendation to a good dog daycare.  We have several in our area, and there are a few I would never recommend.  One lunatic day care operator was seen tossing kibbles all over the floor to keep barking dogs quiet.  Talk about a recipe for a squabble.  I don't know about you, but I don't think I'd like my dogs placed in danger like that.
Dog day care is a wonderful place to socialize dogs that can tolerate being in a group situation.  However, there are some dogs who do better by socializing with small groups, some adult dogs who do better socializing with puppies, some small dogs that do ok with only other small dogs, etc.  Ya gotta know your customers!

Excellent idea about the private trainer lesson. I think I really got lucky with my doggie daycare place. 
 
And you're right, I can think of no better way to start a squabble than by tossing kibble across the floor in a roomful of dogs grouped together for daycare. I would be LIVID!

Wow, I had no idea my post would elicit such a controversial response. Ok, that said there are a few things a feel I need to point out. Fist, ttowndoglover are you trying to tell me that my dog will never show affection toward me due to my over rewarding him. I think that is rediculous, but I must assure you I did not reward him for just being happy to be around me, so that obviously is not the cause. Also, the whole rat anology really did not relate very well to my current situation and was extremely vague. I do appreciate your advice, however I did not find it very helpful.
My dog is a "shy dog" but I did not mean to imply that he was scared of everything, he would be fine( I believe) in puupy daycare and that is difidently something I plan to persue. I have brought him, by himself, to training classes which I must add was very sucseccful, however that was not my major concern. My origianl post was due to my concern that my dog's personality has changed toward me for reasons I was unaware of.
The majority of the suggestions( except for my2dogs) although very much appreciated, I had already implemented. I do spend alone time with my dog,  and I do not belive this change in behavior is due to his interaction with my other dog. They get along well and although she is dominant, he is not scared of her. The average person would not even be aware of her dominace, it only is observed by her guarding her "special treats" from him.
      I am sorry if I appear to be ungratefule for some of the advice, however ttowndog lover, your post somewhat offended me with its scientific jargon that really did not give any helpful advice. Just as a side not, I am now getting my masters in microbial biology so I am not completely uneducated and unfamiliar to the  world of science. Thank you  everyone for the advice,, and if anyone has any more CONSTRUCTIVE help I would still very much appreciate it. thanks all!!!!!