You can, of course, still search for local businesses and view the results as a list or on a map. But the iPad app adds the option to view the results as a grid of photos. As the success of the food recommendation service Foodspotting has shown, photos - particularly at restaurants - can be a huge factor in making a decision on where to go, and by featuring the photos perhaps both users and businesses will feel more compelled to share more pictures on Yelp.
In landscape mode, the Yelp app switches to a new, double-pane view, with the list of search results down the left hand side and the deals about businesses on the right. This new view goes a long way to address some of the headaches of quickly switching between businesses, as you seem to spend less time hitting the "back" button.
The iPad app also lets you write reviews, something you can't do on the iPhone version. (You can write a draft review, but you have to visit the Yelp website to post it.) To be sure, Yelp is still very much focused on reviews, and the company on track to have over 15 million reviews on its site, with more than 6 million added this year alone.
Location's popularity this year, and the rush of other companies - both startups like Foodspotting and giants like Google - to move into this local search and recommendation space, doesn't seem to have hurt Yelp. It says it's grown by 50% this year. Only a small portion of those users use Yelp on their mobile devices - 2.6 million monthly users on mobile versus 39 million on the web. But the iPad app may help more into that mobile category - provided, I suppose, you see the iPad as a mobile device.