This agony is justified because never before have buyers had to wait so long between MacBook and MacBook Pro updates.  Switchers can rejoice as well because many have delayed the purchase of their first Mac as they have waited for Apple to release refreshes.

MacBook
As the table below demonstrates, the longest time between updates was 188 days.  Tomorrow's update will bring the new record to 229 days, 41 days more than the prior record.  As you can see, the average time between the prior four updates was 163 days.  With tomorrow's release the average increases to 176 days.

MacBook Pro
Similarly, the MacBook Pro line has never before experienced such an extended interval between updates.  The new 229 day interval surpasses the prior record by 5 days.  The average time between the prior five updates was 156 days.  With tomorrow's release the average increases to 168 days.

MacBook Air?
The MacBook Air was introduced by Apple earlier this year on January 15.  If the line is updated tomorrow the time interval between updates would be 273 days, a record number of days for the entire MacBook product family.


Demand and Anticipation
Pent-up demand will be a driving force behind sales of the new portable systems that will be released tomorrow.  If Apple reduces price points it could further spur sales to help Apple compete against PC rivals and help the company move product given the economic slowdown currently plaguing many regions across the globe.