PPC, you're usually smarter than this. It's not the same thing at all.
An iPhone web app is a web page hosted on a server.
Palm's apps are local, standalone, with access to internal services. They use HTML, CSS and JavaScript, akin to a widget. That means a lot more people can write little app cards for their own use.
In my defense, it is late over here... ;-)
Poor excuses aside, I made my comment primarily because I haven't seen any developer docs or API references, so it remains to be seen exactly how much local integration "WebOS" will offer.
From what I've read (don't have the bandwidth to watch the introduction videos at the moment), most of the stock apps are heavily web-dependent -- so it may end up being on par with the iPhone when it comes to the level of functionality available without a data connection.
(On a related note: local storage of web apps is actually quite doable on the iPhone. It's kinda hackish solution, using data URLs, but they *are* a standard, albeit esoteric, piece of functionality.)
There are really three things that will make or break this:
1) How much local integration is offered? To my knowlege, there's no published JS API yet, so we have no way to know.
2) How does WebKit perform? My guess is well, but if the Nokia E71 has taught us one thing it's that a good layout engine on a pokey CPU is just slow enough to be annoying without actually being significantly less functional.
3) How fast is the JS interpreter? How good is its memory management? This isn't really an issue if you're just doing the usual jQuery-type stuff, but when you're using JS as your platform's primary language this quickly becomes very important. If the JS interpreter sucks or can't handle non-trivial memory usage, third party apps will be pretty limited in what they can and cannot do.
If Palm makes a well-integrated, high peformance solution with a kick-ass JS engine, they're golden. I really, *really* hope they do -- as a web designer my heart's all aflutter at the thought of using HTML, CSS, and JS to make mobile apps. The iPhone whet my appetite for that sort of thing (I was especially happy to see fullscreen support and local storage introduced), and I think that we're finally getting the sort of computing power needed to do managed apps properly. Still, part of me is reluctant to sing the praises of the Pre until I've actually got a unit and the developer documentation. Palm's kinda got a history (of late) of generating a huge, Apple-esque web buzz, only to fumble the execution (see: Foleo).
<crosses fingers>
---
P.S. Oh, and the other reason I hope it succeeds? Because as soon as it does, Apple will spend a little bit of time to beef up their "web app" functionality. And given that they've got Dave Hyatt and SquirrelFish Extreme on their side, I think their implementation could kick Palms ass... assuming Palm gives them reason to try, that is.