I expect to be playing this game nearly every day for a while, so I'm not too worried personally.
To be honest, though, I do expect this to end up being more expensive for the casual user than people are expecting. People bitched about SF4's update path for some reason, even though the last 4-5 years of SF4 amounted to just $30 total for two substantial expansion packs. At $5 per character for SF5, it's going to add up over time.
Then again, casual players probably aren't interested in having every character in the roster, either, so it might end up being a wash.
I prefer to own a complete chess set from the start instead of paying for individual pieces.