Technically the Level cap is 20 for your class anyways. You can still increase your "Light" level. Just incase you didn't notice, if you watch that E3 video posted earlier in this topic when he is in the loadout screen the top left says 20 but the top right says 29. I hope this makes sense to you guys

Bungie has stated that the Level Cap is 30.

The way it works is that level 20 is the XP cap, meaning that xp alone won't get you any farther. Once you get to 20 you will need motes of light to go farther. The way in which you gain these motes is by finding armor with a light rating. What this light rating does is convert XP to motes of light. The more armor pieces you have the faster it will be converted. The highest level past 20 is 30.

Thanks for info icant wait for the white ps4