The 3rd party Push notifications have been announced two years ago, and are finally available for general use in iPhone OS 3. Apple has put up push notifications as an alternative to multitasking, mainly because multi-tasking apps running in the background would drain your battery quicker and multi-tasking would use more memory. 

Well, it is a fact that the more apps you are running simultanious, the more memory is used. And yes, especially if an application is polling the network for new messages, that can consume battery life quite quickly.
 
So, push notifications is the solution and holy grail for iPhone users.
 
Now, back into real life. I installed Worldvoice, a "radio" application that uses push for notifications of new "broadcasts" and such. So I switched on the push notifications and played around with the application a bit. I then switched the app off and pretty soon, a push message was shown. Cool. I got bored with it, and switched off the individual notification settings for Worldvoice. The general Push setting remained "on" (because I forgot about it) - see screenshot.

After half a day, I noticed that my iphone battery indicator dropped significantly more than I am used to.
 
Did some more tests during a few days and yes, even though you're not actually receiving any push notifications, just having the push notification enabled makes that your battery drains quite a bit quicker than usual. Because the connection to the push server and phone is open constantly.
 
I am now wondering if this push is actually such a good idea. It drains battery, even without using it. This is with only one app, with very few updates. If you have three or four apps, with a lot of updates (say a twitter client with notifications for DMs and Mentions, and an MSN client with notifications for messages, etc), I think your battery will be gone after a few hours. That sucks, and I think is not much different than just run the apps in the background, really.

Do more people have the above experience (or not?) and willing to share their opinion?

Looks like Apple is already prepared for the ban on incandescent lights (the old fashion light bulbs).
 
In the Energy Saver preferences for OS X 10.5.7 they have replaced the bulb icon with and icon showing the compact fluorescent light (CFL). But why CFL and not LED, which is even more efficient and doesn't have Mercury in it?

Spot the difference in the screenshots:

Will others follow? No more "incandescent" WB setting in cameras and imaging software?

 - lots of crap talk about iTunes, Appstore successes and other sales
- 17" "unibody" MBP is a 99% cert
- New Mac Mini w/new intel CPU and no more Firefire (which would suck)
- no iMac update, these will "silently" be updated after MWSF09 I think,
unless they're going to pitch this as a "first quad core consumer
all-in-one desktop"
- updated iLife and iWork suites and
- improvements on MobileMe (again) for functionality in above suits
- no iPhone Nano (but possibly an iPod Touch Nano!)
- demo of Snow Leopard with a few bigshots in the industry and it'll be
available right after the WWDC09 possibly

 I don't think there'll be much iPod/iPhone related stuff, it'll probably
be mostly Mac related. I expect a "special event" by the end of
February, March with more iPhone/iPod announcements.

 There, now I am among those geeks that consider themselves important
enough that their predictions actually matter... (no, really)