They will be fine. One thing, you need to stress to them that they really can't break it and not to be afraid to explore. My mother was always afraid of anything electronic because she was under the impression that if she pushed the wrong button it would break, irrevocably.
While MOSTLY true, my own 75-year old senior in-laws have managed to lock down their iPad 2 twice now. Somehow, they got into the iPad Security settings and set a password that they didn't remember. If they lock it and forget the password, you are screwed other than to re-initialize the iPad. And with iOS5, you have to do this via iTunes, even if you initially set it up without using iTunes.
Its true that they didn't totally "destory" it like they could with a PC. But I consider having to drive 300 miles each way to restore their iPad a pretty big tech support visit. I've taught them to stay the heck away from the security settings since then and now just get the occasional "how do I?" questions. Oh and I did have them both go take a couple of those workshops at the Apple store, but their hearing is so bad that they really couldn't listen all that well in such a noisy setting. And contrary to the late Steve's opinions on the matter, not everyone is an experiential learner...some learn better when they can read a book. I've bought them a few (on their iPad obviously...which kills two birds with one stone IMO).
Nonetheless....this has been far easier to teach them to use it versus the Mac they had prior. That thing was out of service more than in service thanks to their proclivity to just get into button-pressing mode.
A few tips for anyone thinking of being tech support for a senior/iPad user:
1) Set up brand-new Apple ID for them and just use that email/ID for iTunes and official app correspondence. We ran into the new bug (AppleID thinks a new one is already in use) and it took a bit of work for me to fix it. Just use a brand-new one (gmail works well) and keep the password for yourself as well as giving it to them. That way you can monitor their Apple ID activity as needed to ensure that their purchases are working, you can pay for them if necessary, etc.
2) When setting up their email account on the iPad, set up their normal everyday email account. Don't set up their Apple ID account unless you are very sure they know what its being used for (my MIL freaked when she started getting emails to that account from Apple giving her receipts for purchases she forgot she made.....she called her bank to cancel her credit card thinking someone had hijacked her ID...sigh)
3) Show them the iPad security settings and either set up a VERY SIMPLE lock code or NONE at all. If they are in a nursing home or retirement community, I'd suggest you put a lock code onto it but keep it simple. I've been shocked at how many times they've loaned their iPad to someone and that person began making purchases (sometimes not realizing they were spending money). If you choose to NOT put on a security code, make sure they know how the system works and tell them HANDS OFF that setting. Or trust me...you'll have a locked iPad on your hand eventually.
4) TURN ON FIND MY IPAD. Seriously. Just do it. They've misplaced theirs at least 4-5 times. Alzheimers may not be in effect, but old-age short-term memory blows. I've located it for them at least 5-6 times already. One time, it was on a Golf Cart parked at the clubhouse where my dad had left it hours earlier. Recovered, thankfully.
5) Get them a good, sturdy case. Older hands can't grip as easily and arthritis is a bitch making the weight/heft hard to hold for extended periods of reading. The Apple fancy cover is not going to cut it for them. My mom bought a Targus "iPad lap pillow" thing at Best Buy and she loves it for reading.
6) Consider a stylus. It just makes tapping/double tapping easier for them for some reason. They feel more "in control." I bought them a few of the Targus ones.
That's my advice, take it FWIW.