No, to order the known milestone levels:
50: +1 Magic (card becomes Epic)
60: +1 Life
70: +1 Armor
80: +1 Attack
90: +1 Life
100: +1 Magic (card becomes Legendary)
150: +1 Armor
200: +1 Life
300: +1 Attack
400: +1 Armor
500: +1 Magic (card becomes Mythic)
750: +1 Life
1000: +1 Attack
Somewhere in there, your card probably becomes Epic and Legendary (I am assuming at around levels 100 and 250, but I have no data on that at all).
Edit: Added in thresholds at 50 and 100 based on comments below.