You can still use a first generation iPad today and do all of the stuff you did with it in 2010. Yes you can also redownload older apps from the store.
Many older apps have now also been pulled from the store. My iPhone 1 can only reinstall Skype from an old iTunes backup, but not from the store.
I have a first gen iPod Touch running iOS 3.x and a first gen iPad running iOS 5. Of course I have newer devices too.