I bought my MBP new at an Apple store (USA/North Carolina) in late May 2008. Most use of this laptop is at home, plugged in, however I do follow the Apple guideline for calibrating the battery - which I did yesterday. When I look at my battery specs this is the info - is this good for a 15 month old MBP battery? It never charges to 100% anymore - usually 98 or 99 %.
Battery info this morning:
Battery Information:

Model Information:
Serial Number: Sony-ASMB012-3890-625a
Manufacturer: Sony
Device name: ASMB012
Pack Lot Code: 0000
PCB Lot Code: 0000
Firmware Version: 0110
Hardware Revision: 0500
Cell Revision: 0303
Charge Information:
Charge remaining (mAh): 5277
Fully charged: Yes
Charging: No
Full charge capacity (mAh): 5319
Health Information:
Cycle count: 88
Condition: Good
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 12514

System Power Settings:

AC Power:
System Sleep Timer (Minutes): 30
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 30
Automatic Restart On Power Loss: No
Wake On AC Change: No
Wake On Clamshell Open: Yes
Wake On LAN: Yes
Display Sleep Uses Dim: Yes
Battery Power:
System Sleep Timer (Minutes): 14
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 10
Wake On AC Change: No
Wake On Clamshell Open: Yes
Display Sleep Uses Dim: Yes
Reduce Brightness: Yes