Land, and lots of Land. Maybe you have noticed the Copper Ridge subdivision: it just happened. Suddenly.
If you go to the Energy Mines and Resources site here you will see that indeed, it HAS suddenly appeared. In the 5 years from 2002 to 2006 (when Archie was Minister), 527 Copper Ridge Residential Lots were sold. In the SIX years previously, (1996 to 2001), 337 such lots were sold.
Four jurisdictions administer land in the Yukon:
The Yukon government now controls the majority of vacant lands in the territory; Yukon First Nations control their settlement lands; Municipalities administer lands, community plans and zoning bylaws within their jurisdictions. Whitehorse and Dawson City also control subdivision within their boundaries; and The Federal government controls lands consisting of the three national parks (Kluane National Park, Ivvavik National Park and Vuntut National Park) and one Wildlife Area (Nisutlin River Delta National Wildlife Area)

There is information on Future Land Development plans here. And just to jazz up this posting, here is a map of the proposed Whitehorse Copper residential development: