Palette Town, a complex of shops, rides and malls, and one of the worlds largest ferris wheels opened back in March 1999.  Other hallmarks include Toyota Motor Corporation's Mega Web and Zepp Tokyo.  The complex has a 10 year lease with the Tokyo Metropolitan Government which is set to expire in 2010.

According to this Nikkei Business News article, the 125,000 square meter site will be returned to the landowners in June 2010 and the ferris wheel and shopping center complex are expected to be removed.  The area including other lots located near the waterfront (whose leases will also be expiring) will undergo significant redevelopment.  The area will see a large change in scenery in the following few years after the turnover.

As iconic as the complex is, this isn't surprising since nothing is really permanent in Tokyo (and especially when it was economically impacted by the bursting of the bubble economy several years before it opened which resulted in the decade long stagnation with the Nikkei index finally hitting rock bottom in terms of valuation in 2003).

So if you haven't visited Odaiba and Palette Town, you have less than 2 years to see it before this becomes yet another distant Tokyo memory.