We were going to post some long preachy editorial about Tweetie 2.0 being a paid upgrade but it looks like everyblog and their siblingsite has already done that. So here's our quick take:

We're buying it, and happily. We asked developer Atebits why they went the route of a new app vs. an in-app purchase, and the response is worth quoting:

If all I were adding were features, then the in-app purchase route would have been an option (but then again, if all I were offering were features, I'd probably release it as a free update). Tweetie 2 is a fresh start, 100% rewritten, shares no code with the original :). The only thing they have in common is the name.

So bottom line, Apple doesn't (yet?) provide a mechanism for paid upgrades, and in-app purchase allows for more content, not for replacing an old app with a whole new one. So, yeah. This is the option Atebits took, and it works for us. New great app, same great price. And it is a great app, one which took considerable time and effort to make, and we want to support that because we want the developer to be successful enough to make Tweetie 3.0 just as big an update next time.

Sure, scale factors into that -- $3 is a no brainer, so if you ask us what we'll do if a GPS app wants $100 again next year, well... We'll

(And you believed that part up front about not being preachy... ha!)