cosmological constant

[kilofilms]

I was reading Robert Britt's "Hidden Black Holes Finally Found" a couple of days after reading an article in last week's Scince Times where there was a mention that the cosmological constant "should be 1060 times larger than what astronomers have measured" and had a questioin. Is there any idea that all the gavitation in these countless blacks holes that are yet to be discovered could compensate for the relative slowness of the universe's expansion?