Integrated GPUs are fine for most people, who won't be doing gaming or heavy video editing. And surely, the integrated graphics of today are far better then the extreme low end graphics cards found in the old iBooks. Hell, the old iBooks didn't even officially support screen spanning, only mirroring. The only reason Apple gave the iBooks dedicated graphics (if I am not mistaken) was because there was no integrated graphics solution for the PowerPc platform at that time.
GPUs have more functions than just gaming and video editing. For example, in Windows, modern dedicated GPUs can do ALL of the video work. Decoding, deblocking, color correction, deinterlacing, etc. A lowly GeForce 8400M GS can basically do all of the work required to play blu-ray and HD DVD discs without even raising a single degree and the processor just sits back and decodes the audio.
Just look at the difference in playback between OS X and Windows with a dedicated GPU. Not only is the image quality significantly better, but the CPU use is way lower and the GPU is still functioning in a power saving mode. DVDs in OS X tend to use up about 20-30% of a single core. In Windows with a dedicated GPU, your CPU is going to hover around 2-3% and the GPU will be doing all the work in a power saving mode. H.264 video on OS X can eat as much as 60% of one core for a 720p stream. Windows with a dedicated GPU? 2-5%.
Theres also the fact that integrated GPUs have other functions as well. So they can't clock down significantly like dedicated GPUs can.
As for comparing them to the dedicated GPUs in the iBook. Well, the last iBook had a Radeon 9550 in it. The 9550 was based off the infamous 9700, just clocked lower. I had a Radeon 9550 256MB
PCI in a system with a Celeron running at 1.1GHz and 256MB of RAM with XP. It ran both UT2k4 and Half-Life 2 (had to bump the CPU up to 1.2GHz to meet the requirements for that) better than my MacBook does with the GMA 950. We all know the GMA 950 is a better performer than the X3100 in nearly all real world situations.
UT2k4 can't even choke out 30fps at 800x600 on either the GMA 950 or GMA X3100. HL2 can only be played at 1280x800 on a MacBook if all of the settings are set to the lowest. At that point you have to ask whats the point of even playing the game. Half the reason to play the game is the atmosphere created by the graphics. But my old Celeron system could push out 30fps in UT2k4 at 1024x768 with everything set to high. Same with HL2.
Hell, my old HP dv5030us that I bought instead of an iBook had an ATI Xpress 200M with 128MB of dedicated memory (still an IGP though). It could push 30-40fps in UT2k4 at 1280x800 same settings. Same goes for Half-Life 2.
The Intel GPUs are truly the worst of the worst. There is absolutely no reason for Apple to use them. One can't argue size because of the MBP and Apple TV. One can't argue heat either because of them, nor battery life. It's truly awful that the Apple TV gets a GeForce Go 7300 in it and it only costs $229 while the MacBook at $1299, $1400 or so after taxes, gets stuck with the worst of the worst when it comes to integrated graphics.
The iBooks didn't support advanced multiple display functionality because Apple deliberately limited it. There were solutions available that unlocked these capabilities. All of the dedicated GPUs ever used in the iBooks supported spanning, mirror, etc. Apple choose to limit that functionality. The same way the now choose to limit the functionality of the MacBook by using IGPs. If they want to stick us with IGPs at least let us have an nVidia GeForce 7150. Oh and Apple used to actually flaunt the GPU power of the iBook and Mac mini. But now? heh. Upgrading to a GeForce 7150 from the X3100 would probably knock a whole $3 off their profit margin. A GeForce 8400M GS? Oh I would imagine that would cost them maybe $30. Considering their profit margins, letting us have a GeForce 8400M GS in the MacBook would be considered good customer service. But I guess profit matters more than keeping customers happy.
i just bought a new EOL MBP 17" cto hi-res with the 2.4ghz peocessor instead of a new 15" MBP with penryn. They did cost the same, but I now got a nice hires screen and 4gb mem as well a big HD. Inless you really need the cutting edge, getting an EOL is about the safest and cost efficient thing to do. Buying used MB can go very well, very cheap but als horribly wrong! Then again with a year orso of applecare, it could safe a lot of trouble.