Once you fill in the Enter Expense screen there is a short-cut at the top labelled "Enter Payment". 100% of the time that I click this link I am intending to enter a payment for this particular expense.
You should at least pre-populate the Supplier on the "Enter Supplier Payment" screen when it comes up. It would be cool if you also pre-populate the amount fields.
Looking forward to the day this happens :-)
"Pre-populate the Supplier name when you click Enter Payment from the Enter Expense screen"