The 200Hz is good, but I doubt you'll want it set to its maximum. If/when you get the set it would be worth spending some time establishing which setting suits you the best.
In terms of Freesat, that is another debate entirely. At present it doesn't really offer anything extra over Freeview apart from a small amount of HD content. However, with the World Cup finals in HD (as you mention) and the Freeview HD sets not being available yet, I believe Freesat is the way to go at present. Worth bearing in mind also that Freeview doesn't have the same potential for expanding the amount of HD content as Freesat and, given the multitude of problems experienced by customers retuning as a result of the digital switch-over in the North West, I think there is a great deal to be said for the satellite based service. With the current offers of a free BDP-S560 with the Z5800 (but not the Z5500), and the small price difference between the Z5500 and the Z5800 I think its a no-brainer anyway.
Finally, yes BE3 has moved the LCD game on, there is no doubt about that but other manufacturers have also been very successful in this respect. There is a big difference between BE3 and BE2, particularly when viewing SD content. With the better panel in the Z-series as well, black levels are now excellent. Whilst not quite as inky as the blacks on an LED edge-lit set, I feel that the Z retains details in those dark areas more successfully. There is always some slight element of trade-off no matter which way you go.