Kudos to you for walking to work almost every day. I've been testing shoes for Outside's spring/summer Buyer's Guide and am impressed with the durability of Aetrex. The company may be a relative newcomer to the recreational shoe market, but it still has plenty of cred: It's been making orthotics and pedorthic products for more than 60 years.
The comfort and durability of the women's "Athletic Walker" line boil down to these factors: a "Mozaic" pressure-release system in which you can custom-remove pressure points; two removable inserts that give you more flexibility in the fit; a molded, external heel counter that gives your rear foot support; and a shock-absorbing performance insole. I'd recommend the Voyage Athletic Walker ($120; aetrex.com) or the more urban, slick, black Lenex Athletic Walker ($130).
If you prefer a shoe with multiple uses, try L.L. Bean's new Mountain Laurel ($99; llbean.com). The first women's specific hiking/trail shoe L.L. Bean has ever designed, the Mountain Laurel is durable, comfortable, and has a lightweight, waterproof, leather-and-mesh upper for even the sloppiest Boston morning.