1. Plastic case. Aluminum cases and metal back plates have become pretty popular, but they are sooo heavy. It's nice when the keyboard has some weight, but I think things have gone too far.
2. No LEDs. A lot of keyboards have LEDs. Backlighting the keys is one thing, but a lot of keyboards just do it for looks and it gets annoying after a while.
3. Cherry MX blues and browns are great switches. A lot of switches have come on the market over the last few years. I think their proliferation is driven by people wanting something new, but Cherry's blue and brown switches are still better than many other switches.
4. Timeless layout. There has been a drive to make keyboards smaller. I agree with this trend, up to a point. If the keyboard is missing keys you need, it's not a good choice for extended typing. Sure, you can remember the hotkeys for the missing characters, but it's still annoying. Also, there isn't really a standard 60% design, so all the manufacturers do it differently. A ten-keyless keyboard might be _slightly_ bigger than I would prefer, but it's got a layout that has withstood the test of time.