Dh and I are still undecided about whether dd will be an only or not. Some days I feel that our family is just right. But then ohter days I think "oh, I want another baby." So right now it's more of a "when" for us: not right now, but maybe soon. Yeah, I know, confusing, right?

But I wanted to comment about keeping the baby stuff.
We have saved very, very little of dd's baby stuff. We have stuff for her keepsake box, her coming-home outfit, her first halloween outfit, etc. Small things like that. We kept the bouncer seat and the mobile in possible anticipation of another baby, but that's really it. We have donated her clothes and I've sold her diapers. I'd rather a mama who needs them NOW can get use of them.
For practical reasons, we move frequently and we just couldn't see having to move baby stuff from place to place, especially since we are undecided if there would be another one or not. And, as we embarked on the road to being AP, we realized we just didn't as much stuff as we thought we did. We co-sleep, and breastfeed, and used our sling for most of the first year. We also work hard at having savings, so we're pretty confident that if another baby comes along, we'll be able to afford the essential items we need.
Also, I think so many new baby items come out all the time and the safety regulations are always changing. (There are slings out there now that I wish I had had when dd was younger.) Both our parents kept our baby cribs for us to use when we had a baby. Well we couldn't use them b/c baby cribs from 1970's did not meet the safety regulations for the 2000s.

It was good intentions though. (ETA: NOt that you plan to keep this stuff for 30 years, but you know what I mean, right?)
And finally, I think the longer you hold on to something the harder it will be to get rid of it. We don't want to face getting rid of stuff later on if we don't have another baby. DH's aunt and uncle have kept their daughter's baby stuff for over 12 years! They have tried to have another baby, had some m/c, and even tried IVF. They are over 40 now, so that's a big factor in the inability to conceive. But now that it looks like that their dd is going to be an only, I think it's more painful for them to part with their dd's things. Both because it's their dd's "baby things" and also because it's the reminder of the second baby they hoped to have.
My thoughts....