Microsoft's widget (the second one from the screenshot) uses a translation system from Systran and offers 25 language pairs. The widget seems to work only in Internet Explorer and it consists of a dropdown that includes the message "Translate this page" in the available languages.
Google's widget uses a machine translation system developed by Google, that's available for 29 language pairs. The widget works in most browsers and it's actually a Google gadget loaded in an iframe. What I don't like about this widget is that Google cares so much about its branding that it includes a logo for "Google Translate", a link to information about embeddable gadgets and an option to "get this gadget". Microsoft doesn't add any branding to the widget.
Even if it's not flawless, Google's translation system is more scalable and we should see more languages added in the future. And maybe there are better options than adding a translation widget to your page: a mechanism built in your browser that automatically translates all the web pages to your native language or to a language you know.
{ Thank you, Dan. }