I'm lucky enough to own a member of each family of Intel-based Macs. My primary computer now is a MacBook Pro, my wife uses a 17" iMac Core Duo and we have a Core Duo Mac mini connected to our HDTV in the living room for media center functionality.
So, I have some pretty extensive experience with Intel Macs in a home setting. I'm also the IT guy for an ad agency, and we're already adding Intel-based Macs to the network. Said agency is owned by a really, really huge advertising holdings company. That means I'm integrating these Intel Macs into a mid-sized business that has to interface with enterprise applications.
That means I've got some first-hand experience with Intel Macs in the confines of business too.
That means, I can say with reasonable confidence that this Intel transition is not really a big deal at all. I'm pretty sure my wife can't tell the difference between Office running in Rosetta on her new iMac and it running native on her old 1.25 GHz iMac G4 in terms of performance. She can tell that the computer is now more responsive, courtesy the dual core CPU. She notices that iPhoto is much faster and that iChat AV is smoother.
All in all, the greatest compliment the new iMac can receive is how little is said about it. For most home users, I don't think the case to wait is that great. These first generation Intel Macs are miraculously refined. I've seen none of the reports of wide spread issues that most 1st generation issues that often plague Apple products. iLife and iWork scream. Office and other home-based Rosetta apps run fine.
Games are an issue, but that should improve. Sadly, few people view the Mac as a viable gaming platform anymore and even I do most of my gaming on a Athlon X2 rig and my Xbox 360.
For business users, the story isn't all that different. Office is still fast enough. All of our custom SQL applications perform acceptably in Rosetta.
The exception is people involved in content creation. If your livelihood is an Adobe app, digital audio, digital video or some other content gig, stay away. Your ecosystem is too complex and is still probably not all that used to OS X, much less Intel chips. Even when your primary apps are ported, the countless plugins you use will probably take even longer.
Treat your current PowerPC Mac with love and affection. You'll be together for a while longer yet.
I'd like to wrap this rambling post up with some thoughts on each shipping Intel Mac. Be aware that startup times on all these machines is considerably faster than all the most recent PowerPC Macs.
This may be the perfect desktop computer. The Core Duo makes it snappy, while keeping it cool and quiet. It takes up little desk space, but has a large, bright and easy-to-read display. I can find no fault with the iMac as it stands today.
In addition to what myself and others have written, you need to know one more crucial detail. This computer is not a laptop. Oh, it looks like one. The size is just right, and if begs to be used on the couch or on an airplanes. Do not be fooled.
At first everything will be great. You'll marvel at the speed of this machine and wonder if a desktop is hidden somewhere. People will comment on the attractive form factor and you'll get cheers of delight demoing Photo Booth.
Then, the heat will begin. It starts with a little itching on the thighs, and before long your pants catch fire. This is by far the hottest laptop I've ever encountered. I think you could get a cold cup of coffee to a nice pleasant sipping temperature with the bottom of this machine.
Other than that, I'm in love. It's a big sticking point though.
There are many people griping about the integrated graphics in this machine. As long as you've got a gig or two of RAM, there's nothing to worry about. My mini is connected to an HDTV via VGA. Everything is smooth as silk. Front Row, the RSS feed screen saver, Keynote 3D transitions and build and even the little ripple with you add a Dashboard Widget animate without a hitch.
Again, I'm impressed by what the Core Duo does for a machine. It's much more responsive than the PowerPC based mini. I haven't tried GarageBand yet, but I suppose that would run nearly as well as it does on my MacBook.
Plus Front Row on a large HD set is just really cool. I've been pleasantly surprised by how well the Bonjour features work, even over 802.11g. Music, photo and even video sharing is seamless.
I'd say the road to Intel has a lot less bumps than we've all anticipated.