Ken,
If you or your wife like art, there are several interesting galleries in the Aladdin's Mall. In fact, I find the whole place more interesting and affordable than the one at Caesars. Caesar's is more upscale...it has interesting things like the moving statues, but not much I'd spend money on.
Anyway, there is an inexpensive restaurant in there called Max, which is great for lunch. They have $3.95 and $5.95 specials for lunch, and they are really good, believe it or not. And Aladdin is my favorite superbuffet.
Harrah's new buffet will be open by then, and sounds interesting. Among other things it will have a Brazilian BBQ station. Also, Clint Holmes performs there in the evenings (a favorite, personality-driven, very versitile singer). If you plan to do an afternoon show, Mac King's magic is here.
Society of Seven performs many afternoons at MGM. They aren't cheap, but mid-priced. They are very dynamic performers. There's a Wolfgang Puck Bar and Grill in MGM that I like, and also Emeril's Fish House (haven't eaten in there in years, though).
As mentioned above, Bellagio's Conservatory with the flower sculptures is well worth your time.
There is a Titanic Exhibit at the Tropicana that is really interesting. You can do the whole thing in about an hour, and its worth your time.
I am guessing you'll be on foot a lot. Make sure you have a good jacket, and a scarf and hat...if it is windy you may want the scarf for your face. One night, go to the bridge between NYNY and MGM and take in the Strip's lights. Or go to the top of the Stratosphere. Or take the monorail at night for the lights.
If you have the time, go downtown one night. Ride "The Deuce," going on the upper level so you can see the lights of the strip. Then go all the way down to the Fremont Street Experience (a sound and light show, there's a different one each hour after dark).
If you are wanting to save money during the day, there is a Chipolte Grill Mexican food ("fresh Mex) right on The Strip just north of Harrah's, and lunch there would be reasonable.
Hope all this helps.
Fern