Measure the Rope
How long can you wait until you make a change at the coaching position? In United's case, Tom Soehn started his tenure with a pair of decent results in the Champion's Cup, then went on a three game losing streak that even prompted don't panic assertions from this blog and "Fire Soehn" threads on message boards that were in jest for some, but quite serious from others. At some point, though, even if I still believed in Tom Soehn, he could have lost enough games that a change would be warranted regardless of my feelings. Let us theorize a number representing the quantity of consecutive losses a team could endure before the coach is fired. This limit would be different for each coach, depending on reputation and results to date. Accordingly, below is my estimation of the number of games each coach can lose, consecutively, until they are fired. Now, I've also amended that with the number of games they should be allowed to lose in a row before being replaced, since Calvijo could probably murder a puppy in the Technical Area and eat its still-beating heart and somehow not get fired. Accordingly, here's what I think...
Consecutive Losses Ideal
Team Coach Before Replacement Limit Notes
Chicago TBD 5 5 
Chivas USA Preki 7 5 
Colorado Clavijo 6 1 
Columbus Schmid 4 4
D.C. United Soehn 6 6 
Dallas Morrow 5 5
Houston Kinnear 8 7 
Kansas City Onalfo 4 4 
L.A. Gullit 8 4 
New England Nicol 7 7
New York Osorio 4 6
Salt Lake Kreis 5 4 
San Jose Yallop 8 8 
Toronto Johnston 5 5
 Of course, this depends on who the coach eventually is, and what kind of acquisitions they make, but in general I think, given what we saw with both Houston and DC last year, teams in general will give at least five games to start the season with losses to any coach.
 Probably has more slack than he deserves, but I could be wrong. If Chivas gets off to a hot start, then the ideal number I had was wrong, but I think if they start slowly, the front office will wait too long to make a change.
 Should be fired already, and should be fired at earliest opportunity.
 I think Tom has some slack, but depending on what players fill in on the off-season, if things don't go well I think he could be in line for the axe sooner than people think. Of course, I hope we never find out, but that's my feeling about these things.
 Pretty much has earned the cult of personality in Houston.
 I know it is far too early for such things, but my guess is that KC might be the first team to make a move next year.
 Note: I'm assuming that Alexi stays on as GM, in which case Gullit gets fired only when Alexi determines that his job might be in danger.
 Reading RSL Coverage, it is interesting to see how much Jason makes that job about him and his personality. If the team continues like they always have, Jason has invited everyone to view it as a failure of him personally, and they should. He has almost dared the world to give him less rope than other coached might have.
 It's an expansion team, so patience will be in order. However, even expansion teams will make changes at some point.