Why only 8kb per page? I just want to know how they came to 8kb when striking a balance between:
smaller page = more page splits
bigger page = longer to look through to find value

I expect there are many more pros and cons to having a bigger page but if we could start again would we pick 8kb again?

I'm not saying it's the wrong decision and I know it would be a massive change to the product to alter the size.

Also I know 8kb was chosen a fair few years ago now and I wonder does it still make sense when rows are likely to be longer now due to new data types?
At the SQL Server conference I attended in Sydney in 1999, Richard Waymire said that Microsoft's intention was to allow a variable page size in SQL Server 2000 but that it turned out to be really difficult, so they put it in the too-hard-basket and went with 8k as a compromise.