will there come a point where the difficulty becomes to high for cpu miners?
No
Elaborate please why that is. One shouldn't accept an absolute answer without explanation. I'm for LTC succeeding but will not accept what people say blindly.
Thanks!

If the LTC difficulty rises to 12 billion, many people might say that is too high! Others might say it is too far!
But if LTC are worth $12 Billion each...is the difficulty too far or too high?