The Timbuk2 Freestyle iPad/iPad2 Messenger Bag is the most unique bag in the mix. I mean that in a good way. It doesn't look like you're off to the jungle for a weekend, and comes in a variety of colors and patterns. All in all a great sporty looking bag that will hold your iPad Air just great.
And of course, like all bags on this case, it will hold a lot of other stuff besides. After all, now that you have a bag, you might as well put in your phone, keys and planner.
The chocolate brown colored CaseCrown Vertical Multi-Pocket Messenger Bag combines brown with orange in a look that I'd also call sporty, though it's a bit more businesslike than the Timbuk2.
The CaseCrown bag is more of a traditional vertical messenger bag model. With various pockets, including a padded one for your iPad, this too is a very practical bag.
The STM BAGS Scout Extra Small Shoulder Bag is the first on this page not specifically marketed for the iPad. In fact, it will hold laptops too: up to 11 inch. I like the rough and ready look. Like you might be off for a hike just now. And yes, this bag WILL hold a small water bottle to go with that (well protected) iPad.
The Kensington Sling Bag is the only real business style bag on this page. I do think sling bags are a great alternative to traditional messenger bags, especially if you bike to work (which many do here in the Netherlands).
And yes, this bag too has an internal compartment for your phone and plenty of room for keys and date book.
The Genuine Leather Crossover Sling Bag for iPad looks classy on men as well as women. This is a real stylish bag with plenty of extra pockets for all your stuff. For business as well as home use.