JDW, isn't it interesting what goes around comes around? Everything was bigger, better, faster, then as technology allowed desktop power to be miniaturized for a price, it became about being smaller and more portable for everybody. Now I'm seeing a trend where folks are getting frustrated with laptops and iPhones and want some kind of larger interface, be it a monitor they can attach or accessing their files on a full sized computer or device.
Just to correct your perspective about the iPad, Jobs has long since learned his lesson about expandability. The iPad will initially have accessibility to a USB digital camera, or flash card via a dock interface. Apple has already approved serial device implementation on the iPhone, so I would expect to see it on the iPad too. This means, there is a direct way to tap into the processor. So the hooks are there, and jail-broken, likely capable of anything a developer desires. The iPad also grants direct disk access to networked computers allowing files to be directly transferred from a users desktop, which also opens the door for screen sharing, and thus access to a remote computer's hardware. And keep in mind, most of what the expansion slots on the SE family were used for is built-into the iPad already. And Bluetooth is another method for integrating hardware wirelessly. So, the iPad is already leaps and bounds ahead of where the 128K started (despite having the exact same screen dimensions). What Jobs is doing this time around is controlling the software, while opening the hardware up to be versatile enough to do anything, something that could not be done as inexpensively on the 128K. Jobs couldn't control hackers in the 80s, so he locked them out of the ability to easily modify the hardware. Today he does it with licensing and controlling access. It certainly hasn't stopped the hackers, but they have to constantly battle Apple on every update to maintain their freedom. More trouble than it's worth for me.
And to be fair, I don't think Jobs was anti-expandibility as much as he wanted to control the expansion. He didn't want people to be able to add anything to directly access the CPU which might cause instability with the experience. If the expansion can be controlled, then he seems to have always allowed it. What I find truly interesting though is that the same formula he used with the 128K that was frowned upon by the engineers, is being gobbled up by the masses: devices with fixed RAM! You can't even upgrade the storage capacity as you could on the 128K. It's classic Jobsian philosophy, when the user is ready to upgrade, they don't expand, they just buy a new one ... and it is working!! It wouldn't be possible without the explosion of the middle-class credit card consumer who evolved during the 90s. Man talk about a guy ahead of his time.
And finally, the SE had an expansion slot, but the paucity of cards available for it then and now, demonstrate exactly the market position it held. People who bought the SE were entry level power users, or small businesses, with en eye for expandability ... but no real intent to do it, and most didn't. By the time they needed Ethernet, they were ready for more power. The SE/30 on the other hand was truly powerful enough to justify the investment in expensive expansion cards. It replaced the compact application in professional environments, or full sized professional application in budget environments. If anything, I would say what killed the professional compact was the PowerBook. By the time the Duo came out in 1992, PowerBooks were running 68030 chips on a bus as fast as the SE/30, and the Duo offered the same expansion via a PDS direct slot, as well as color expandability, in a smaller format with a larger screen. The installation of many of the popular expansion cards on the SE/30 were made far more elegant in the form of a variety of micro, mini, and full-sized docks. The Duo remains my favorite Mac after the compact form factor. If you had the money and wanted portable the Duo was the answer, leaving compacts for kitchen cabinets, or students desks and limited use applications.
And why is it these tiny devices are finally taking off? The technology has been around for a while. It's the ability to enlarge the screen! Why is it 640x480 seems tiny on a Color Classic, when 1024x768 is perfectly acceptable for the iPad of the same dimensions? Because it can be scaled quickly and easily as needed. That's why these tiny devices are suddenly being embraced. Now you can have it all, compact, stylish and powerful, and don't need to put on your jewelers glasses to use it. You need it bigger for presentation or tired of pinching and stretching? Just plug it into your LCD TV.