Update 4/16: One thing I should probably clarify here is that the existing buildings which are initially slated for demolition to make way for the new Nintendo building are an office park, and do not appear to contain any Nintendo offices at this time. The building which would be demolished after construction of the new building is completed does belong to Nintendo though.
Aside from Microsoft, Nintendo of America is probably the best known corporate citizen in Redmond, but recent events have led people to wonder if the company might be headed for greener pastures. During 2007, NOA moved their sales and marketing departments to new offices in San Francisco and New York, and also sold off a large parcel of land they owned at the corner of 148th Avenue NE and NE 51st Street to Microsoft, who will probably use it to continue with the aggressive expansion of their Redmond campus once some of their current construction projects have been completed.
In spite of these recent moves, a recent land use application filed by Nintendo with the City of Redmond seems to suggest that they intend to use some of the money that the DS and the Wii have been printing for them remain in Redmond for the foreseeable future. According to the Notice of Application (PDF link) that was posted on the City of Redmond website about a week ago, the plan initially calls for the demolition of six existing buildings (plus a seventh building to follow once construction has been completed) to be replaced by a new 275,250 square foot building with an auditorium, cafeteria, and exercise facility, as well as a new 820-space parking garage. It appears that the new building will have an overall square footage that is actually slightly less than the seven smaller buildings that it will be replacing (which total about 283,500 square feet. Based on the documents filed so far, It appears that the two other Nintendo buildings in this area (including the one where DigiPen is located) will remain undisturbed, at least for the time being.
To get a slightly better idea of what the new Nintendo headquarters (or at least the grounds thereof) might look like, there is also a Site Plan (PDF) and a Tree Preservation Plan (also PDF) on the City of Redmond website. For comparison, a map of their existing campus can be found here. So far, there doesn’t seem to be much to report here just yet (the notice of the land use application was only posted last Friday,) but I’ll watch this and report on any new info that appears on this.