Good for you! I wasn't trying to suggest John Ritter was "iconic" as Jack Tripper. I only mentioned him (and Reeve) because they were, as I said, the only celebrity deaths that really affected me more than any others, and Hagman is no different.
The producers are working on a way to address his passing on the show: http://www.hollywoodreporter.com/news/larry-hagman-death-dallas-prepping-393767
For those interested, TV Guide this week (the issue with Matt Smith on the cover) has a lovely, 12-page tribute to Hagman.
For a lack of a better phrase, Hagman and JR were the soul of Dallas. How do you go on? Damn. I would hate to be in their shoes.
More spoilerific casting news for the new season, and most notably who TNT has lined up so far to attend J.R.'s funeral on March 11. Spoiler: SPOILER I for one, cannot WAIT to see the inevitable Sue Ellen/Mandy Winger reunion!