"With the just announced Starwood devaluation for level 5 and 6 properties, it looks like the real bonus in 2003 will be any program that can keep the benefits and reward levels we currently enjoy!"
Guess AC's Aeroplan fits that bill, BB, and is starting to look good again: No changes from last year [

], and a few more benefits for mid-tier Elites.
And while AA hasn't changed anything else, an increase in award "prices" takes effect later this year, so even it doesn't fit your criteria. KL is changing some things after its exceedingly generous offer to non-NAmericans [amazing how many residents of this continent managed to qualify though, with the help of overseas postal addresses], as I believe is LH.
Given the precarious nature of US and UA, I doubt we will see overly generous promos from competitors, since AA and NW will pick up new members by default, even without offering up much more than tier matching. UA is doing the best it can by offering an extra few months to earn top tiers.