Mac comparison. Is it worth the extra $500?

I'm deciding between 2 computers, a macbook, and macbook pro.
I want to know if the difference between them is worth the extra $500.
Does 2gb of ram vs 4gb of ram make a big difference?
Does 2.4Ghz vs. 2.53Ghz make a difference?
Is there a battery life difference? (this is a big one for me, the new MBPs have better batteries, do the MB's have the same ones??)

MACBOOK (13.3")

Enclosure Precision aluminum unibody Processor 2.4GHz Intel Core 2 Duo L2 Cache 3MB shared System bus 1066MHz Memory 2GB (two 1GB SO-DIMMs) of 1066MHz DDR3 SDRAM (PC3-8500); supports up to 4GB Hard drive1 250GB Serial ATA; 5400 rpm Slot-loading optical drive 8x SuperDrive (DVD±R DL/DVD±RW/CD-RW) Graphics NVIDIA GeForce 9400M graphics processor with 256MB of DDR3 SDRAM shared with main memory2 Video Built-in iSight camera; Mini DisplayPort output port with support for DVI, VGA, and dual-link DVI (requires adapters, sold separately) Display 13.3-inch (diagonal) LED-backlit glossy widescreen display, 1280-by-800 resolution USB Two USB 2.0 ports (up to 480 Mbps) Audio Built-in stereo speakers, built-in omnidirectional microphone, combined optical digital input/analog line in, combined optical digital output/analog line out Networking Built-in 10/100/1000BASE-T (Gigabit) Ethernet Wireless Built-in AirPort Extreme Wi-Fi (based on IEEE 802.11n draft specification)3 ; built-in Bluetooth 2.1 + EDR (Enhanced Data Rate) module Hardware accessories 60W MagSafe Power Adapter, AC wall plug, power cord, lithium-polymer battery Height 0.95 inch (2.41 cm) Width 12.78 inches (32.5 cm) Depth 8.94 inches (22.7 cm) Weight 4.5 pounds (2.04 kg)4
VS.


MACBOOK PRO

Enclosure Precision aluminum unibody Processor 2.53GHz Intel Core 2 Duo L2 Cache 6MB shared System bus 1066MHz Memory 4GB (two 2GB SO-DIMMs) of 1066MHz DDR3 SDRAM; supports up to 4GB Hard drive1 320GB Serial ATA; 5400 rpm Slot-loading optical drive 8x SuperDrive (DVD±R DL/DVD±RW/CD-RW) Graphics NVIDIA GeForce 9600M GT graphics processor; and NVIDIA GeForce 9400M graphics processor with 256MB of DDR3 SDRAM shared with main memory2 Graphics Memory 512MB GDDR3 Video Built-in iSight camera; Mini DisplayPort output port with support for DVI, VGA, and dual-link DVI (requires adapters, sold separately) Display 15.4-inch (diagonal) LED-backlit glossy widescreen display, 1440-by-900 resolution Expansion Two USB 2.0 ports (up to 480 Mbps); One FireWire 800 port (up to 800 Mbps) Audio Built-in stereo speakers, built-in omnidirectional microphone, combined optical digital input/analog line in, combined optical digital output/analog line out Networking Built-in 10/100/1000BASE-T (Gigabit) Ethernet Wireless Built-in AirPort Extreme Wi-Fi (based on IEEE 802.11n draft specification)3 ; built-in Bluetooth 2.1 + EDR (Enhanced Data Rate) module Hardware accessories 85W MagSafe Power Adapter, AC wall plug, power cord, lithium-polymer battery Height 0.95 inch (2.41 cm) Width 14.35 inches (36.4 cm) Depth 9.82 inches (24.9 cm) Weight 5.5 pounds (2.49 kg)4