Yesterday, we alluded to some of the developer partnerships eBay announced for its new X.commerce platform. They were paraded out in greater detail following John Donahoe’s keynote, representing the first big functionality injections to the platform.

As background, X.commerce is meant to be the uber platform for individuals and small businesses to create commerce-enabled websites and apps. This broadens and builds on eBay’s longstanding tools for selling goods through its auction marketplace.

Furthermore, the whole point is that X.commerce is an open platform for the masses of developers to design cool applications that can be sold to or used by the growing ranks of commerce-based small businesses (both e-commerce and retail).

At X.commerce’s core is Magento, a low barrier website creation and management tool that eBay bought in June for a rumored $180 million. Plugging into that workflow will be a number of other tools that boost analytics, search marketing, social and other things.

— eBay-owned product inventory company Milo is integrated so that online stores can be more easily populated with rich product images, descriptions and real-time inventory levels. That can be helpful for both e-commerce and in physical stores.

— Adobe will plug in as the analytics engine. This includes standard metrics on what items are selling and how. It also importantly provides information on what to do with that data, such as crafting a better marketing plan to optimize revenues for top selling items.

— Kenshoo will be the engine that drives traffic to these sites, as it does best. Kenshoo Local will plug in to manage keyword optimization and other search marketing necessities that build a better presence across the Web.

“You can select the products you want to advertise, then select Google, Facebook and others,” said Kenshoo Local GM Sivan Metzger. “That triggers a chain of events that leads to a Google ad or a Facebook ad, customized and optimized to those interfaces.”

— PayPal is also not surprisingly integrated into X.commerce. This happens through a new feature called PayPal Access. This could do for commerce identity what Facebook Connect did for online authentication.

Like Facebook Connect, sites can offer users the availability to authenticate themselves and their billing information by a simple sign in. From there, all credit card and shipping information is authenticated. No more typing in all that info (great for mobile).

— Facebook itself will integrate its open graph features — the fabric of social connections stitched together by the like button. This will be broadened (just like Facebook announced at F8) to a set of other buttons (think: “bought,” “want,” “recommend”)

The idea is that it will facilitate “social shopping,” sending these actions bouncing around the news feeds of the 130 people to whom the average Facebook user is connected. That is hoped to lead to more back links, traffic and thus sales.

These are some powerful integrations and the overall goal of X.commerce is ambitious. I’m not convinced yet that social media and commerce aren’t an unnatural mashup. But the point is that opening it up to legions of developers will find the killer app, if it exists.

We’ll provide a deeper look in an upcoming BIA/Kelsey report.