We've heard through the tip line during the last few days that the latest Tango ROM updates for Lumia devices features a slightly new Marketplace.
In short, the 'Nokia Collection' is being renamed to 'Nokia Market' on all Lumia phones, a move that we applaud ("Collection" never really fit). The move is accompanied by a icon change for the Marketplace as the traditional bag is flattened for a more Metro look but also features a big 'n' logo emblazoned on the side.
The new logo can be seen in an unboxing video for the Lumia 610 in Vietnam at about the 3:25 mark
Certainly this is an unprecedented move by Nokia obviously done with the blessing of Microsoft. It also shows how deep the Nokia-Microsoft partnership can go with Nokia slowly but surely exerting control over the OS and user experience with the focus on Lumia and less on "Windows Phone". Even with all the advertising here in the US for the 710 and 900 the words "Microsoft" and "Windows Phone" are never mentioned, which is probably a good thing for now.
Users of the AT&T Lumia 900 should probably expect their Marketplace to be updated with a future software update which will most likely include Tango.
Source: Nokiapoweruser, XDA forums, Verge forum; Thanks, Dave S., and Simon G., for the tip!