Some suggestions.
Driving is key; I suppose you aren't within driving distance? Be prepared to spend $$ on cabs. And I'd stay in a hotel with a concierge that has easy access to cabs or shuttles.
For great shopping, I'd hit North Park
http://www.northparkcenter.com/. It's the largest privately owned mall in the country and it's full of great art that is all owned by the family that own the mall. It's upscale, though after the expansion now has some lower priced stores. Dr T and the Women filmed at this mall - it's where high society women have always shopped (near the swanky part of town).
The Galleria is huge, and has several hotels attached to it. It's more N Dallas though. It's upscale as well, with an ice skating rink. I just don't think of it as unique as North Park.
If you end up downtown, or are just curious, the flagship Neiman Marcus is downtown. Be sure and eat at The Zodiac Room while there; it's delicious!!
http://www.neimanmarcus.com/store/info/store.jhtml?storeId=01/DT&_requestid=38368 Be aware that NM only accepts their store card, AMEX, check, and cash. I always write a check when I dine there. The North Park NM has changed their Zodiac to a Cafe that looks good but I haven't been there yet.
Downtown Dallas has tried to be more than all business and has mostly failed. Fort Worth has figured it out; they have a great mix of business, condos/apartments, bars/clubs, restaurants, and retail along with great live music. You can take the TRE train
http://www.trinityrailwayexpress.org/ to Fort Worth and visit the zoo, the museum district, or Sundance Square (downtown area -
http://www.sundancesquare.com/). You could always visit the Stockyards or Billy Bob's (world's largest honkytonk LOL -
http://www.billybobstexas.com/).
As far as hotels,I would avoid staying near Fair Park. Downtown Dallas would be okay if you are okay with knowing there won't be much within walking distance. We stayed at The Magnolia a few years back and it was awesome. They had a free shuttle to West End so we took that to grab a bite to eat but there wasn't much else. But, being downtown would likely mean access to a shuttle or constant cabs. Downtown Dallas to Downtown Fort Worth is really only about 30 miles, too (or abt an hour on the train).
Also know that in 2 months, it's going to be hotter than hell here. Plan air conditioned activities until late evening if possible. (maybe find a great hotel with a nice pool?)
Good luck planning!