Engadget notes that Sony Ericsson has its own channel for its Android phones in Google’s Android Market. The article’s author also notes that the “My Apps” section that lists apps installed on your device has been moved off of the main Market page.
However, this kind of branding change is not unusual. The Motorola Droid on Verizon Wireless, for example, replaces the My Apps link on the main Market page with a link to apps that Verizon chooses to feature to its Android using customers. You can see this in the side-by-side screenshots here. The left screenshot is from Engadget’s article and shows the Sony Ericsson link on the main page while the screenshot on the right is of my Motorola Droid and shows the Verizon link in the bottom left of the image.