I'm not up on all the deals but it is definitely worth going there. I lived there for two years in the early 80's; I was on a sub in Pearl Harbor. I really enjoyed the scuba diving out there! It's amazing when you roll off the zodiac in Pokai Bay and the water is over 100 feet deep and crystal clear! I could see conchs crawling on the bottom!
I also went to Maui and the big island. All three islands are nice and have many things to do. Since I lived there for two years I was able to do things that someone on vacation would never have time to do -- such as some of us on the boat made friends with locals and got a great lesson on how to luau a pig including how to pick the best rocks from the stream, etc.
I went back in 2000 on a business trip for a conference and it was much more crowded; a lot more development in downtown Waikiki. I managed to get a few dives in on the weekend before the conference started. It was funny, one of the other people on the dive boat and I were discussing mayor Eileen Anderson's efforts to halt excessive development back then. From the posts above, it sounds like the development continues.
If you are into scuba diving here are the places I dove at. These are all places you can go to on your own (at least back then). Make sure you check on all the latest rules and follow all safe dive practices.
Hanauma Bay - very nice, lots of coral to look at, max dive around 60 feet or so. You can see moray eels; they won't bother you unless you bother them. Don't put your hand inside a hole in the coral; it might be a Moray eels "house". Don't go past the end of the bay; the Molokai Express current is along the coast there and will take you out to sea. I don't care how strong a swimmer you are; you can't make any progress swimming against it. Follow these simple rules (and any new ones you might hear about) and Hanauma Bay is a very nice beginner's dive spot.
Blowhole - around the bend from Hanauma Bay. Great shore dive. See the blowhole from underneath! If you go into the cavern under the blowhole make sure you are qualified for and have the gear for cavern diving. Also, you need to stay on the cavern floor (sand) so that when the waves come in you don't get smashed against the ceiling. Also, we did night dives there, one guy from the boat would come along and read a book while standing watch next to our lantern on shore. One of the best dive I've ever made was a night dive there; we were about 1/4 mile offshore and were in bioluminescent sea life. We turned off our lights and waved our hands around while green trails of light followed our arms through the water. All while we could hear the whales offshore "talking" to each other! :-) They were probably laughing at us!
Electric Beach - just offshore of Hawaiian Electric's Kahe Power Plant. Just google "electric beach Oahu" to find location, etc. Nice diving and snorkeling location. Caught a spiny lobster there. The lobster in Hawaii are like the lobster in Florida; they don't have claws. They have two really long "spines". So, if the restaurant serves you lobsters with claws and tells you they were caught fresh locally . . . . .
Pokai Bay - we left on a zodiac from the marina so this one isn't a shore dive. But if you can dive there it is amazing. Crystal clear water, max depth about 100 feet. Many, many moray eels! Just remember not to bother them! If you do, they will bite! If you don't bother them, you can get within several feet without any problems. The huge conch shells I saw from the surface had seaweed, etc growing on them so when I saw them moving from the surface it looked like the plants were moving.
Shoreline near Pipeline - lots of places along the North shore where you dive on the coral heads. Most of these are shallow dives close to shore.
On Maui the road to Hana is very scenic. Really nice road along the coast with lots of one lane bridges. However, I heard from someone at work that it is so busy now you have to miss the "rush hours" in the morning and evening due to the daytrippers to Hana. Also, going up to the observatory on Mount Haleakala (all short vowels, pronounce them all) is fun. You can go bike ride back down (up if you can), hike in the crater, and so on. It was cold and foggy when I went up there, if you can believe that.
On the big island the Volcanos National Park is fun if you like lava and the smell of sulfur! :-D There were active vents when I was there.
There are many more things to do on all the islands. There are also lots of other dive spots. I didn't get to them all, unfortunately I was doing more diving on the sub than I was with my scuba gear! :-D