What's the significance of Hong Kong in the Shadowrun world? Is there a specific Shadowrun reason people are excited for this, or is it just because it's a cool city?
The answer is a little complicated. When Shadowrun was in it's prime, it was pushing the 80's cyberpunk feel real hard. Japanacorps were a big scary thing. America was afraid Japan was gonna take all our jobs, with their superior product, technology, and work ethic. So some of the biggest and scariest MegaCorporations in Shadowrun were Japanese. Mitsuhama, Renraku, Fuchi, Yamatetsu, and Shiawase made up 5 of the "Big 10" AAA corporations.
Currently (IRL), Japan isn't going to take over shit, but China might... kinda?
FACTUAL INTERLUDE
The present licenseholder for some old FASA products (Shadowrun, Battletech) is Loren Coleman. Loren Coleman, when he wasn't busy writing shitty books, stole 700,000 dollars -with some insiders claiming an even higher number- from the company coffers to fund an expansion on his house. Meanwhile, he told writers that he had no money to pay them what they were owed. The majority of writers left. A block of them went on to create Eclipse Phase, a good game you may have heard of. Current writers for the IP make far less then industry standard, and generally work on a freelance basis. This has obviously had an impact on quality. tl;dr Anything written for the universe for the past 7 or so years, sucks ass.
BACK TO ANSWER
The main hub of Shadowrun adventures takes place in Seattle. A UCAS (United Canadian and American States) territory surrounded on all sides by foreign powers. Hong Kong too is a 'western' city surrounded by foreign powers, with the added helping of psuedo japanacorp fear.
Its more interesting then Berlin, less interesting than Vegas or NYC.