Level 1: Dash
Level 2: Evasion, Bonus Feat x3
Level 3: Spring Attack, Sneak Attack +1d6
Level 4: Critical Sense (+1 attack bonus)
Level 5: Expert Tumbling
Level 6: Whirlwind Attack, Sneak Attack +2d6
Level 7: Bonus Feat x3
Level 8: Defensive Roll
Level 9: Sneak Attack +3d6, Minor teleportation
Level 10: Improved evasion, Critical Sense (+2 attack bonus)
This way a player could try the full class out and still get the same epic feats as one that did staggered levels. For instance a Rog 13/Assassin 9/ WD 8 and a Rog 10/Assassin 10/WD 10 would both be able to get the same selection of feats: epic prowess, epic precision, epic dodge, expose weakness, PTWF.
Hmmm... now that I think about it this does seem a litte "cake and eat it", as the 10/10/10 would be able to get epic dodge and offensive epics VS the staggered possibly not being able to get ED, depending on what level you got improved evasion that is. :/ Damnit! Did I just sabotage my own suggestion?
Maybe toss expert tumbling or a sneak attack out?