1st thing to check -> the libraries you've pointed to - like MOST Arduino libraries - are written with Uno/Duemilanove in mind which DOES have SPI pins at 10,11,12,13 & you can use pin 9 for the RST
The SPI pins for Mega however are 50 (MISO), 51 (MOSI), 52 (SCK), 53 (SS) as per the Mega's hardware page: http://arduino.cc/en/Main/ArduinoBoardMega
. This means you'll probably need to start by tweaking the code to point to the right pins. Furthermore, you probably also need to check with the ATmega1280 microcontroller's datasheet whether the same SPI commandsets apply as compared to the ATmega168/328 families. Note that Arduino's SPI library for some reason doesn't work right with the LCD - probably because the SPI library is designed for 8 bit SPI while the LCD uses a 9 bit SPI convention.
My suggestion is -> first try making the LCD work with the mega using "bit-banging"/ShiftOut SPI. Then try using the hardware SPI features of the microcontroller.
As an aside, i've the same breakout board working & have just recently released a graphics library for it called ArdGrafix6100 http://code.google.com/p/ardgrafix6100/
. This is released under the Mozilla Public Licence v. 2.0 & currently supports Philips controller & is mainly built for Uno/Duemilanove. However, if you're interested in helping port it for Mega/Epson controller, would be happy to collaborate :-)