These are the reputation levels and the number of reputation points needed to reach each level:

-100 points --- User is infamous around these parts
-50 points ---- User can only hope to improve
-10 points ---- User has a little shameless behaviour in the past
0 points ------ User is an unknown quantity at this point
10 points ----- User is on a distinguished road
50 points ----- User will become famous soon enough
150 points ---- User has a spectacular aura about
250 points ---- User is a jewel in the rough
350 points ---- User is just really nice
450 points ---- User is a glorious beacon of light
550 points ---- User is a name known to all
650 points ---- User is a splendid one to behold
1000 points --- User has much to be proud of
1500 points --- User has a brilliant future
2000 points --- User has a reputation beyond repute

These are only the first set of Reputation levels. The points needed to gain each level may change in the future, and more levels may be added. Check this post in the future for any updates to the levels.