It is so, so very fun. :)
My summer setup weighs in close to 10 lbs even. This is
packraft plus accessories (cruiser deck, thigh straps, booster seat),
inflation bag and repair kit.
My paddle weighs about 2 lbs, the pfd about 1, the boat about 5, and sundries make up the rest.
Shoulder season kit I have not weighed b/c I haven't settled on one yet. Dry suits or wetsuits weigh much more than rain gear but can be necessary (or simply worth the weight for the warmth).
My boat is a 'Paca, so add some ounces if you're average height and need a Yak, or subtract if you want a Scout. Yaks seem to be the most popular. MYOG pfds can be well under a pound, and more expensive paddles can save weight too.
Total weight depends on what sort of water you want to paddle and when, honestly. Serious whitewater setups will weigh 15 lbs or more, with all the basics plus a whitewater deck, throw bag, helmet, and other equipment. Summertime class I-II floats could be well under 10 lbs--check out Dave C.'s blog for a review of the Alpacka Scout, which is a fine option for many uses.