Copied from Slickdeals...which was copied from Reddit.
The only difference between Heroic and Deluxe Editions are:
[customspoiler=TLDR: Horse Armor]
Summon Mistfire Wolf Elite Skill:
I don't own it, but never heard any praise about it. The empty spot among your Elite skills may annoy you, but you aren't really missing out on anything. The Wolf is weak, sadly.
Mini Rytlock:
A mini pet follows you around basically, does nothing. Rytlock looks kinda cool, but there are many more awesome minis.
Golem Banker:
This is a personal golem you can summon, that acts like your bank for 2 weeks after using it. Slight conveniece, though I don't think you would be using the bank a lot in the first few weeks. Currently useful only in key farming, it saves you a minute or two per run at most.
Chalice of Glory:
I think they removed it by now. Spvp had a currency from launch called glory, which you could use to buy pvp stuff. They've been slowly removing glory from the game and this is kinda worthless, if it still exists.
Tome of Influence:
Grants the guild you are representing 1k of influence, which is a currency a guild can use to upgrade the guild. You can buy the same amount for 2g I believe, which is pocket change. Useful at launch when there wasn't much gold and much influence, not really important today. Could use it for your personal guild, that would act like a bank.
[/customspoiler]