[Ayiu]

Ah you're right, the only difference is the Beta access. UK retailers are only giving the beta with LE and EE though and in NA you just need to pre-order the retail game.

Prices for NA: Limited $80 and Epic $150

I found this in the GoW official Forum:
You have access to exclusive content that you can unlock and carry over to your Gears of War 3 gamer profile

Exclusive Beta Unlockables

- Flaming Hammerburst
Complete one match by Sunday, April 24 to permanently unlock.
- Flaming Lancer
Complete one match during the week of April 25 to permanently unlock.
- Flaming Sawed-Off Shotgun
Complete one match during the week of May 2 to permanently unlock.
- Flaming Gnasher Shotgun
Complete one match during the week of May 9 to permanently unlock.
- Beta Tester Medal -- Wear it proudly, Gear.
Complete one match in the Beta to permanently unlock.
- Thrashball Cole -- Unlock Thrashball Cole to play as Augustus Cole as he was before Emergence Day -- a legendary Thrashball athlete known for his ferocious, flamboyant style.
Complete 50 matches in any game type to unlock for the Beta period.
To permanently unlock, complete 10 matches as Thrashball Cole during the Beta period.
- Gold-Plated Retro Lancer -- Before the chainsaw bayonet was deployed at the beginning of the Locust-Human War, the original Lancer assault rifle had a large fixed blade.
Complete 90 matches in any game type to unlock for the Beta period.
To permanently unlock, score 100 kills with the Gold-Plated Retro Lancer during the Beta period.