There’s a big difference between IT and Business. Technologists seek absolute certainty; while Businesses thrive on uncertainty.
A good case study would be Microsoft's launch of Windows 95. It may be the crappiest piece of OS at that time, but the businessman in Gates saw that since most software were rotten anyway, it’s ok to release one that’s crappy with style.
Advice for the IT Guy
It doesn’t matter what you think, at the end of the day; if the emperor feels that the invisible clothing looks good, it will be good. Any further negativity will label you a whiner.
Advice for the Business Guy
Once in a blue moon just humour the IT guy to a cup of coffee. You might just learn a thing or two, and thank God that you’ve outgrown being a geek.
Advice for the Dark Manager
If both the Business and IT give thumbs up, the project will be a glorious success. If either one of them says otherwise, make the person who says NO the key decision maker. At least you’ll be erring on the side of caution. However; if you’re the one that’s forced to say YES to some higher up, make sure you’re not cc’ed any emails, have them sign everything and practice your selective amnesia..