You are one point away from a 31-talent skill in all trees so I would indefinitely respec either ret, prot, or holy. In my opinion, at this level, you should go for the 31-talent skill.
Your options are holy shock (holy), holy shield (prot), or repentence (ret).
I personally think you should go prot and be a tank. Holy shield & blessing of sanctuary & ret aura is phenomenal for tanking. At this level, you will start doing more instances and a good tank is more valuable than a DPS build/class. Note, prot is horrible tank against spells... so you will need to inform your group to take out casters. Do note that 1/2 your damage will be from ret aura, sanctuary, and holy shield.
If you are to go holy or prot, you will need to change your gear to almost entirely +int and +stm. Holy shield has a 8 sec cool down and should be up when you are fighting either a boss or 2+ mobs constantly. Also, make sure the mobs are in front of you ;-).
Holy is good. I am not sure if you want to be a secondary or primary healer in the group. Holy shock requires a lot of mana, which you might not be able acquire.
Ret is good too, but tanking +2 mobs will be difficult depending on the DPS of your group and your gear.
Whatever you decide, in most cases, you should be clear about what role you can actually fulfill. A ret pally can rarely primary heal or even secondary heal a group...
I created recc builds for each; others please recc.
Holy
http://www.wowhead.com/?talent=sVeh0xzhxo
Prot (need a fast one hander (2.0 speed or less) and a good shield)
http://www.wowhead.com/?talent=aZV0tI0hzgd
Ret (keep that 2hander if it is better than level 40 greens; this is similar to the other suggested build with the exception of no benediction; your mana will always be low i would suggest judging crusade then seal of command with limited judging of command)
http://www.wowhead.com/?talent=qZZxf0tMcuV0o
If you go prot, you might want to read up on how to be a tank with a pally. there are innumerous posts here on the subject.
cheers!