Today is the day. Probably.
Starliner is on the Atlas, Atlas is on the pad, valves are purged, potential water ingress points are sealed and/or covered, weather looks pretty good.
As much fun as it has been to bag on Boeing, this test really needs to succeed and not reveal any more significant problems; now that Soyuz flights are pretty much off the table ... forever, we need that dissimilar redundancy for manned flights. Awesome as SpaceX has been, they're not infallible.
Ars has another article making the case that Boeing is the reason the commercial crew program was allowed to exist; had it just been SpaceX and other NuSpace players, Congress wouldn't have approved and funded the program. It's only because Boeing decided "what the hell, we do space good, we'll play" that the program exists.
ULA is retiring the Atlas V in a couple of years, and planning to use the Vulcan Rocket to fly Starliner. Will Vulcan be ready by then, given the problems with Blue Origin's BE4 engine?
They have enough Atlas V's (enough components to build them, anyway) to fly all the contracted Starliner flights, all of which are for ISS crew rotation. Any Vulcan flights would be for some contract that hasn't been made yet, for some other purpose, with a completely unknown deadline, making this impossible to answer.
The only other use I've seen proposed for Starliner is Blue Origin's Orbital Reef, which itself would be dependent on New Glenn and just as subject to BE-4 delays. And even if that wasn't so, Starliner wouldn't be needed for it until some time in the 2030s.
I'd like to think that Starliner will have missions beyond 2024, so if that is when Atlas V ends (presumably this has something to do with running out of RD-180 engines and not buying any more) then it seems reasonable to ask what else it could be launched on, and as you correctly point out, both candidates (Vulcan and New Glenn) rely on Blue Origin's BE-4 engine, the development of which hasn't exactly gone smoothly. I have read that Starliner can also be flown on Delta IV and Falcon 9, but of all the four options, Falcon 9 is the only one that is human rated.
Tory Bruno has to be getting just a little bit worried.
There are not going to be any more Delta IV flights, and only a few more of Delta IV Heavy. The Delta IV production line is now the Vulcan production line.
Blue Origin fans (which do exist, for some reason) assure me that all the talk about further BE-4 delays is pure FUD and everything's going perfectly well with flight engines being tested and about to be delivered any day now.
As of March,
The manager of Blue Origin’s rocket engine program has left the company:
According to company sources, the first two BE-4 flight engines are in final production at Blue Origin's factory in Kent, Washington. The first of these engines is scheduled to be shipped to a test site in May for "acceptance testing" to ensure its flight readiness. A second should follow in reasonably short order. On this schedule, Blue Origin could conceivably deliver both flight engines to United Launch Alliance in June or July. Sources at Blue Origin and United Launch Alliance say development versions of the BE-4—which are nearly identical to the flight versions—have been performing well in tests.
So assuming that timeline has held, the first engines should be finishing up their acceptance testing this month.
Of course, until we actually see the bastards mounted on a stage, take any announced timelines with a salt lick. Yes, this is literally rocket science. Yes, developing a new engine is legitimately hard. Yes, these things always take more time and money than you initially expect.
But
damn, guys, don't do everything in your power to make it look like you're half-assing it.