How is "be wanting" different from simple present, past, present perfect form of "want"?
It looks like to me that there is some emphasis on the speakers' mind when they use progressive forms. Here are some examples of my corpus search.
1. Everybody came into this game wanting to go 3-0," running back Buddy Rodgers said. "We've been wanting to show people that we are a true team this year.
2. I've been wanting to give a keynote address at MacWorld for years, Loevner joked.
3. Heã€€said he was wanting a van or something.
4. If any of you lads are wanting to join me merry band, you're welcome.