Well....70 is only a bit more than 7 years away.....pretty sure I'll still have, and ride my sport bikes.
That said, I am looking at adding a "low and slow" bike to the garage. The new Indian looks interesting and I've sat on one and found it comfy and "Low". Wish they would bring out a Warrior to go with the Chief.
Just got to ride the 2014 all new Suzuki DL1000 for 100 miles Tuesday. A really great machine, but too tall for my short legs. If I could drop the seat a couple of inches I could learn to like that bike quickly.
So, in other words.....I plan to keep riding. Sport bikes, cruisers, ADVs ..I'm even thinking of a trail bike to putt around in the woods.
You don't quit riding because you get old. You get old because you quit riding!!!
Don't be a pussy...there was a 75 year old man around here a few years ago would ride his yamaha R1 130 miles each way to the track. Ride the track all day and then ride home. Don't be a fatass, keep healthy and you should be able to ride until you are a very old age