See my post above this one. Eventually, most of your family members (casual users) will not even have a Mac with Lion to worry about. Macs will continue to be bought by, and designed for the "pro" users, like you & me, and many other tech-involved industries. It's also why Windows won't just up and disappear.
However it is the "home and casual user" that will more than likely not own a PC at all. These devices will be all they need for "free time" computing.
Hint: take a look at how you're using your Mac today, and give some of the 3rd party devs/utilities a chance at how you could "possibly" work faster and better. You will be a "Post-PC-Desktop-Island-Tech-Support" in short time, so no need to show your family or friends anything on the desktop in the future. Just make it work for them on their i-Devices, as fast and easy as possible.. and quit worrying about the "pro GUI" of Lion. Grandma won't need it... the kids won't want it... and you'll get used to it
Admittedly, Lion is a transition toward a desktop-not-required future. We're still living in the present, however, and those of us who are the family and friend "tech support" are facing easy of use issues with this release. The iPad is something I'll be working to get everyone transitioned to, but it's going to take time, and I have yet to find that tree that grows money.
The iPad has limitations regarding data storage, and still must be synced with a Mac in order to be updated. I stopped by my Mom's iMac this morning and decided to drop real world numbers into this Lion discussion. If we're going to be talking about transitioning these users to the iOS, then we're going to have to deal with their real world usage (top level only):
Applications = 53 Items, 4.61 GB used
Documents = 77 Items, 4.19 GB used
Movies = 78 Items, 448.21 GB used
Music = 3 Items, 381.89 GB used
Pictures = 244 Items, 158 GB used
And that's just from a grandma who belongs to a garden club (and composes monthly newsletters in Pages) and has a couple grand kids (she's the typical "snap-happy" grandma who loves her digital camera, and fills it routinely). All respect to Apple for the iOS, but it's not at a level to handle her usage right now in a solo capacity. I'm going to be replacing her iMac in the next few years with a new 24" model because she needs that big screen.
When it comes to Lion, I'm sure that you and I can handle anything they throw at us. My concerns are for those people who use technology for interaction with family and friends any don't know the first thing about keyboard short cuts, their fingers don't work as well as ours for gestures, and their eyesight leaves a lot to be desired. With the color and design changes to Lion, I'm very concerned that Snow Leopard will be the end of the road for those users. If iOS devices are going to be the space they dwell in, then these devices are going to have to meet their needs and I don't see that happening with real world capacity restraints. Lion may be making some people's lives easier, but it's also going to make a lot of people's lives harder and I don't think Apple is appropriately addressing this demographic from all that I've seen in their screen shots.