Except you can bet on getting about 24 hours of sleep time on a Windows machine (my HP laptop lasted a little over 24 hours on a full charge) compared to the ~4 weeks of standby you get on a MacBook.
This is completely dependent on the hardware and how well the OEM (in your case, Apple) optimized it. My Thinkpad used to get 2 weeks on standby (nowadays it just wakes up and hibernates after a while).
My Vaio Z got about a week of standby on a battery with about 30% charge left. I guess it really depends on the machine.
As others have noted this is perhaps more a hardware issue than software, but it does highlight the real advantage at the core of apple's business; a tight synergy of hardware and software.
Seen elsewhere with improved battery life of the iPhone vs android phones, for example.