You may have and exploding keg if the fermentation takes off again, but I doubt that will happen. Pressurizing the keg to 30 PSI will probably inhibit any further yeast activity that you might see. If you are really hoping for it to keep fermenting then you may want to rig up an airlock on the keg.
If you kept the primary too cool then you may have had an incomplete fermentation, or you may have caramelized a lot of the malt extract during the boil, leading to a high FG, or maybe the yeast weren't very healthy...
Bottom line: does it taste like green beer should? You might just have a sweet beer. Drink 'em if you got 'em!
Kelpie Home Brewery, Lafayette Colorado
Primary: Creek Dog Stout x2, Two Dogs IPA, Grinning Kelpie Wheat
Secondary: empty :(
In Bottles: Belgian Wheat