About Ethernet connection: simply overkill. IMHO, note IMHO, N900 is a cell phone, with wifi and multimedia capabilities. Should it have RJ-45 port, it would A) look ugly as hell B) add extra cost C) be useless to most users. And it has 3G data transfer, too!

About USB OTG: not so overkill. To me, quite useless - with the sole exception of USB mass memory connection, and with a huge question mark, game controller. Bluetooth can be used, too, and is more elegant with a small device like N900 (it's smaller than the controller!)

Please, try to remember, that purpose of N900 is to be Internet tablet, media player, backup camera and a cell phone. Everything else is just frigging cool candy! It is very hard, or in many cases impossible, to make the device do something not supported by the hardware. The power lays in software, instead! I have, for example, completed some of my programming homework using gcc on my current N810 - just how cool is that?