The 2008 event which introduced the two events was october 14th, so you have until 10/14/09 to buy applecare for the 2.4, since you have one year to buy applecare. If the CL seller can provide the original sales receipt or the serial number to check on the apple support site, you can use that to determine your deadline. One day over the first year when it was originally purchased, and you're out of luck. ALWAYS buy applecare on an apple portable. Always. You can buy applecare for a discount on ebay (always make sure you're getting an unopened box) but you may not have time for to do this.
The displays received a stealth update in the first quarter of 2009. Some umb readers are also showing improved display quality with 10.6's tweaking of the gamma level. If you can read the threads and figure out how to check what the mb's display is, avoid the 9c89 display. It is truly horrid and has spawned most of the controversy about the original screens.
If the mb doesn't already have 10.6, the $249 on applecare, and $30 for 10.6 will eat up the savings over a refurbed 13" 2.26. With a refurb you can at least defer the cost of applecare for a year.
Agree with previous posters to get the 2.26 because of the battery, sd card, firewire, ram capability and display if you have to get one now. The buyer's guide is listing the mbp at mid product cycle, with 114 days since the last update and an average of 120 days between updates on average. Will the next update be a minor speed bump or a whole new (quad core) cpu? I don't know, and any other opinion on the subject will be just that; an opinion.
If you truly need a laptop now, get the refurbed 2.26.