Multiple reports suggest Microsoft's expertly crafted Touch Cover is a little more delicate than anticipated. Users, in Surface forums, are complaining that their cover/keyboard combo is literally ripping at the seams after moderate use. That doesn't say much about their durability, especially when Microsoft touts how carefully it constructed the technology.
The Surface discussion only chugs along to three pages, so the issue might not really be that wide spread. One user says they simply returned their keyboard for another, so there's that. These aren't just some low-cost accessories people are using to protect their devices; the Touch Cover by itself starts at $119.99, which definitely isn't cheap.
We haven't noticed anything with our Touch Cover, so these could be isolated incidents. It's unclear how rough or careful affected users have been. If tears are occurring at the seam, it may just be a case of shoddy construction. Either way, keep an eye out on your covers to see how they're holding up.