Chambliss is almost begging for a primary challenge at this point.
I highly doubt McConnell will have a serious primary opponent. Paul seems to have made friends with him.
I believe Mitch just hired as his campaign manager one of Rand's top aides from 2010 (who also served as a top aide to Ron this year). Rand described it as "very good", saying that "We're excited about it. I think Jesse will do a great job for him." Mitch said that "we've established a very good working relationship." It's not really a new development; Mitch's chief of staff Josh Holmes advised Rand's 2010 campaign, and there was that Frankfort unity rally back then too. That's why Mitch was featured in Ron's tribute video at the RNC, and why Rand was the featured guest at a McConnell fundraiser in March (followed by Mitch headlining a RAND PAC fundraiser later).