[Alessi]

Look at many long running game shows and how many of them stay the same as their original incarnation for long. These things are nearly always tweaked to iron out kinks and improve things, I can't see how this will be any different.

Indeed was wondering if the Popmaster format on day one is the format we come to know?

Millionaire, Deal or No Deal, Pointless, Radio 2’s Couch Potatoes - invariably they get tweaked over the years. 

The Weakest Link and The Chase are the same format as launch, I think?

The latter two pretty much though think The Weakest Link tweaked the end game and The Chase added minus offers a few years in - initially used very rarely but now used almost daily.

Although those examples were still really popular concepts from the start (the TV ones anyway) before the tweaks were introduced.
I'd be interested in any examples of something which really didn't work at all at the start that was then rescued and became a successful format.