Blending and extending, which has come back into favor in the current leasing market, will remain a big trend for the foreseeable future, Riguardi said. It's one of many opportunities for tenants in these days of reduced rents and greater landlord concessions. The current climate also offers plenty of chances for upgrading the location and the space, and for using market leverage to enhance non-economic lease provisions.

At the same time, the financial stability of owners at both the entity and property levels will remain a focus for tenants. That being said, Riguardi pointed out that about 100 Manhattan office properties suffer from shaky financing, but there haven't been nearly as many foreclosures in 2009 as might have been predicted a year ago, due largely to reluctance on the part of lenders.

Although Lauren Picariello, JLL's Boston-based VP and director of research, noted that overbuilding was limited to a handful of markets compared to the downturn of the early 1990s, Riguardi observed, "It's always an issue of supply and demand, and clearly, supply outweighs demand" at the moment. Looking ahead to an eventual recovery, Riguardi predicted, "2010 will be the year we find a bottom," and JLL predicts that rents and occupancy nationwide will begin modest growth around the third quarter of 2011.