A power steering hose was replaced at about 70,000 miles, while still under the extended warranty.
A few software updates have been performed, mostly free of charge.
At 70,000 miles, the brakes and rotors needed replacing. I did find it peculiar that the rotors had worn and needed replacing, but they indeed had. Price was $700.00 for the entire brake job; 4 rotors, all new pads, labor. Expensive, but not horrendous.
At 85,000 miles, I replaced the front stabilizer link rods, as they were making a clicking sound. The rods were $85.00 for the pair, and I was able to perform this simple repair myself (easy as pulling a wheel unbolting the old part, and then re-bolting on the new part).
Most recently, at 100,000 miles, we have determined the transmission is failing. It has not been a sudden, catastrophic failure, but instead has gradually given several thousand miles of warning (delayed shifting response, and it slips occasionally - becoming more frequent with higher miles). Though this is indeed a frustrating realization, somewhat costly auto repairs do indeed happen. The Borg transmissions for the particular years of the XC70 2001 and 2002 were somewhat prone to this failure. Subsequent models with Swedish Haldex transmissions don't bear the same problem; only the Borg models.
Cost for a Volvo factory exchange transmission is $3000 plus labor. Wholesale or jobber price for a re-manufactured transmission from Volvo is $2,600, but you need to own a repair shop to qualify for the discount... and then there's labor. Total price for the job done right will be around $4000.
Though we're not happy about it of course, I often think of our friends' 2 Chrysler mini-vans, who have replaced their transmissions like clock-work at 50,000 mile intervals. Some are on their 3rd or 4th trans! The independent Volvo-only repair shop did indicate that owners who regularly service their XC70 transmissions every 30k miles are seeing no problems, even after 200,000 miles.
So, I do have to take some responsibility here (we've only had ours serviced once, at 50,000 miles). When we get the new trans installed, we'll have it serviced every 30k.