As much as some of us might love to see CBS try a new one-hour game at 10 AM Central and Pacific if they drop TPIR after Barker's retirement (I had an idea for one, but some folks here shot it down...), or a pair of half-hour games, I can't help but think as well that Barker's retirement will mean an end to morning games on CBS, unless they decide to rerun a bunch of TPIRs for several months as a temporary fill-in.
The network hours in daytime have reached the point of stagnation. The last NEW network show to debut in daytime was NBC's soap "Passions". NBC also expanded the "Today Show" by another hour, ABC gave an extra half-hour back to their stations when they cancelled "Port Charles" and the only radical change I envision CBS making down the road if they drop TPIR is perhaps expanding "The Bold And The Beautiful" to an hour, though it would probably screw up a lot of established noon news shows on many of their affiliates.
These days, it's more interesting to see what the affiliates add to their daytime schedules from September to September, as well as an occasional January, March or April. At least, for what it's worth, the era of affiliates bumping network daytime shows is pretty much history.