Barack and Joe will soon vacate their Senate seats and head off for the executive branch, and there's a huge amount of speculation afoot as to their replacements (I was going to put some links in here, but there are so many that I could never supply a representative sample). In both cases, it's been speculated that the governor may install an older or otherwise placeholder not likely to seek a full term. Personally, I think this is a good idea, though not necessarily for the reasons why people say the governors would do it.
In the case of Illinois, speculation centres around Blago (for the love of God, Fitzgerald, get him outta there) giving the job to someone like Emil Jones, since, apart from fulfilling the highly presumed "token black" role (which I have mixed feelings about, as an aside; 85% of Illinois is not black, and Barack Obama's whole candidacy was about trying to get past that kind of thinking, but at the same time there's a strong case that the constituency should be represented there), would be unlikely to serve a full term, which would free him politically from upsetting somebody who wanted the job.
In the case of Delaware, as per some speculation, Joe II is looking to hand the job over to Joe III (aka Beau), which handoff is somewhat complicated by his son being out-of-country for the next nine months (which, as an aside, is ridiculous; he's the sitting Attorney General of Delaware: stay home and do the job the voters elected you to do), so he wants a Benjamin A. Smith type (the bridge between Jack and the then-too young Teddy Kennedy). As reported elsewhere, Beau has in the past declined to just be appointed to a job (as with the AG job he has now), running for it instead, which is a good strategy, given he's inevitably seen as riding on dad's coattails.
I think both are a good ideas, for a simple reason: they preserve voter choice. The election system is massively weighted for incumbents, and if Blago and Minner/Markell go looking for the next 30-year incumbent, well, they've installed a thirty-year incumbent. This is particularly notable in Delaware, which has had exactly one consequential election since Joe was elected in 1972: Tom Carper's unseating of William V. Roth in 2000. If Beau Biden returns in nine months and is ready to try for the seat, and John Carney wants it too, then let them run the primary and the voters of Delaware will decide who they want.
Delaware also highlights another issue I have with the way a lot of states do the Senate replacement procedure: there is no reason whatsoever to wait two years for a special election in lieu of having one right then. Indeed, Massachusetts and Alaska both have laws to that effect, installed recently (and both likely to be used very soon, given Stevens' implosion and likely-seeming ridiculous reelection and Kerry's likely Cabinet job). Delaware highlights the absurdity because of the comparison between how the House does it: if Joe resigns on the 20th, and, on the same day, Michael Castle drops dead of a heart attack (god forbid, he's a gentlemanly fellow), a special election would be held for Castle's seat, and Joe's replacement will be appointed for two years, when their districts are exactly the same.