Blizzard tried to balance all professions to be equally powerful. In earlier times of World of Warcraft rogues often switched their professions to get the one with the most advantages for them or their group. In most cases this was leatherworking for fabricating drums. In Wotlk almost all professions are balanced and only have little differences in their benefits.

As a jewel crafter the rogue can craft unique and epic gems. He can use three of them in his own equipment which makes it easier to reach the meta gem requirements. Additionally, the epic gems have higher stats then normal ones.

A blacksmith improves the armor with new sockets on gloves and wrists. As an enchanter the rogue can enchant his rings with attack power enchants which gives him considerable more damage. As a leatherworker a rogue can improve his wrists with powerful attack power pads. This improvement overwrites a normal enchant but it is cheaper and way more powerful.

If you choose inscription you have access to very powerful shoulder enchants. They are not only stronger than normal enchants but you don't have to farm reputation at the sons of Hodir.

Alchemists get a bonus from elixirs and flasks through "mixology". They need twice the time to expire and are also stronger.

Don't choose tailor and engineer. Both professions are too weak for rogues. As a tailor you have special threads in your cloak which are weaker than a normal enchant (for rogues). Engineers have some nice toys for gloves and belts. But this is more a fun profession. Only rocket boots can be effectively used in arenas. For PvE this profession is a waste.