We're discussing this now.
"Soft" cap of 20 and items like the titan marks can raise your level higher. At least that's we think.
The guardian in the pic has 9 titan marks. Someone in our clan said he read that on one of the grimoire cards it discussed these in more detail how titan marks upgrade your armor.
Motes of Light is given to you by the speaker, and you get that from exp after level 20.
I can't confirm this, but it seems logical.
The guardian level is 29. Even if people are saying " 20 hard cap" blah blah blah. People are not going to say "oh I'm level 20 with 113 motes of light which makes me level 29". There going to say " I'm level 29".
On a previous IGN video you can hear Urk mention that the level cap is much higher than what we've seen.
I'm hoping for a rather quick initial progression to let me access all of the game but then a slow and rewarding climb towards the higher levels.