You can use the Hints by Topic drop-down in the sidebar to easily see just the iPhone tips. If you're at the other end of the spectrum (and you're a registered user), you can set your preferences so that you never see iPhone tips. Just visit your account's Preferences screen, and place a checkmark next to iPhone in the Excluded Items section of the page, then click Save Information.
And yes, I'm very much looking forward to October, when I expect we'll start seeing a flood of hints on Leopard, iLife 07/08, and iWork 07/08 (assuming those are also released with/near 10.5). But after 26 months and 938 tips on 10.4, there's just not a lot of top-secret 10.4 information to be found. So until 10.5 comes out, we'll have the usual mix of application tips, AppleScript and Unix tips, and yes, now iPhone tips as well.
-rob.

