Jobs introduced a 500MHz iMac, with 128MB of RAM and a 20GB hard drive, for US$999. It comes in indigo and snow, which Apple resurrected after retiring the colour earlier this year in favour of Flower Power and Blue Dalmatian.
He touted another model in snow and graphite that runs at 600MHz, with 256MB of RAM and a 40GB hard drive, for US$1,299. These two models are available now.
The third model, which will be available in September, runs at 700MHz, with 256MB of RAM and a 60GB hard drive for US$1,499. It will also come in snow and graphite.
Each of the new models will include a CD-RW drive. Previously, the iMacs ran at 400MHz to 600MHz.
Still, Jobs' speech lacked its typical surprise ending when he unveils the latest and greatest. Instead, Jobs ended with a preview of iDVD 2, an update to the program that lets consumers put their digital videos onto DVD. The new software is set to come out in September.
What Jobs didn't announce -- a much-anticipated, flat-panel iMac -- grabbed analysts' attention.
"None of the announcements are as dramatic as the introductions that Apple made earlier in the year...which could limit their impact on sales in the second half of the year," said David Bailey, an analyst at Gerard Klauer Mattison.
Bailey said he was particularly concerned that Apple made comparatively minor changes to the iMac, while hiking the price of the entry-level iMac by US$100 to US$999.
"Price is more important rather than less important" in this difficult economy, he said. However, Bailey said he is hoping Apple will come out with more dramatic changes in time for the holidays.
Goldman Sachs analyst Joe Moore speculated that Apple's aging iMac product line is the reason the company's financial outlook isn't better. Apple watchers were hoping that Jobs would unveil a brand new iMac in his keynote speech, Moore wrote in a research note. But Jobs didn't deliver.
"It seems that the bulk of the shortfall in September is coming from the iMac lineup," Moore wrote, referring to the company's current quarter.
Mac fans at the trade show weren't particularly thrilled either.
"There wasn't anything that seemed truly exciting," said Thomas Simonet, a professor of journalism at Ryder University in New Jersey.
"The conference was disappointing compared to last year's, and it didn't live up to the rumour that Apple might introduce a handheld device."
"I was expecting more out of the hardware lineup," said Jeff Ondovic, another attendee. The only thing Ondovic was happy about was the company's decision to get rid of the Power Mac G4 Cube. "Last year's conference was definitely better."
Shares of Apple were off US$4.28, or more than 17 percent, to US$20.82 in midday trading.
Jobs also introduced three faster, slightly restyled Power Macs, which had previously run at 466MHz to 733MHz.
The new entry-level model runs at 733MHz. There is also an 867MHz model. The third model has two 800MHz chips.
The 733MHz Power Mac, which sells for US$1,699, includes 128MB of memory, a 40GB hard drive and a CD-RW drive.
The 867MHz version, priced at US$2,499, includes 128MB of RAM, a 60GB hard drive and a SuperDrive, which reads and writes both DVDs and CDs.
The high-end machine, which comes with two 800MHz chips, sells for US$3,499 and comes with 256MB of memory and an 80GB hard drive.
All three new Power Macs will also sport a new silver-colored case, Jobs said. The high-end model will be available next month, and the other two models are available now.
Jobs used the early part of his keynote address to focus on Mac OS X, Apple's new operating system.
Jobs gave a preview of Mac OS X 10.1, which he said would ship in September and offer support for playing DVD movies, along with new networking features and improved handling of digital photos. Jobs also promised faster launching of applications, resizing of windows and other performance enhancements.
"You name it, it's faster," said Jobs, who appeared in his trademark blue jeans and mock turtleneck.
Jobs also announced that the company plans to open four more retail
"We think they are a great complement to the other great retailers we have out there," Jobs said.
Aiming to demonstrate support for the new Mac operating system, Jobs showed off 10 programs under development for OS X, led by Microsoft's Office business-application software, due to be released this fall.
