The next big thing with WordPress is Ecommerce plugins that can handle big sites. Right now there are some solid plugins but most can’t handle things Magento can. Here are some of what I think to be 3 solid plugins.
Jigoshop is an eCommerce plugin for WordPress developed by professionals with years of experience delivering online shops for global brands.
WP e-Commerce is a free bolt-on shopping cart that lets customers buy your products, services and digital downloads online. It is really easy to setup, you don’t need any programming skills. It supports all major payment options like PayPal and Google Checkout. You can also use your own HTML and CSS to have complete control over the outlook of your online store.