NYC Foodies spending 2 days in Vegas.
Looking for best upscale steak/best italian.
Carnevino covers both, actually, though your mileage may vary given the fact that Batali is all over NYC.
While not as "upscale" as Carnevino, you might want to take a look at Andiamo downtown. A great "Vegas experience" with top quality ingredients and service....truly billed as an "Italian Steakhouse." On the Strip, I am a big fan of David Walzog, the exec chef at SW. For a NY reference, he ran the steakhouse at The Monkey Bar and Michael Jordan's at Grand Central Station before Steve Wynn enticed him to come out to Vegas for his namesake steakhouse when he opened the Wynn. The great thing about David is that he is "on the line" and what comes out of the kitchen is his.
Two Italian restaurants at the Wynn/Encore to consider…Bartolatta at the Wynn for seafood, and although not especially inventive, Sinatra at the Encore is a very refined and pleasant experience, and always very good.
Being from your same area (work NY , live CT) I would consider SW for steak. It's expensive but it is really hitting on all cylinders. And it is really a "hip" whimsical setting. I would also agree with josephni and go to Bartolotta. Again expensive (although Bartolotta will make SW seem like McDonalds in terms of cost) but the quality and variety are unsurpassed. Their pastas are very underrated in my opinion and choosing some is a way to make the cost SLIGHTLY more bearable.