One question raised by the announcement of the DSi, and specifically its removal of the GBA slot and its promises of a built-in browser: would that browser be Opera, and will the DSi contain extra RAM to allow the browser to run? The old DS version of the Opera browser required a GBA RAM cartridge, after all.
According to Opera CEO Jon S. von Tetzchner, the answer to both questions is "yes:"
Yes, the DSi has more RAM than the DS Lite. In addition, with integrated Opera coming with the DSi, it will use RAM more efficiently.
It'll be interesting to see how this affects the DS software library as a whole. Will game developers opt to go DSi-specific in order to access that additional memory, or will it largely go unused? Another question: what will this mean for DS homebrew? Many homebrew DS games already require the Opera GBA RAM pack to run: if the DSi is hackable for homebrew, that means that the DSi might quickly become the preferred system of choice for emulators, source ports and the like.
Operating Systems are less important: opera [Tech Tree]