I don't do mobile development, but it strikes me as odd that features like this aren't available by default on most phones:
full text search: searches all address book contents, messages, anything else being a plus
better call management: e.g. a rotating audio call log, meaning you always have the last N calls recorded for your listening pleasure later (your little girl just said her first "da-da" while you were on a business trip, you had a telephone job interview, you received complex instructions to do something etc.)
bluetooth remote control (like e.g. anyRemote, but available by default on a bluetooth phone)
no multitasking capabilities worth mentioning
and in general no e.g. weekly software updates, making the phone much more usable (even if it had to be done over USB, rather than over the network). I'm sure I was dumbfounded by the lack or design of other features as well, but they don't come to mind right now.
To clarify, I'm not talking about smartphones here: my plain, 2-year old phone has a CPU an order of magnitude faster than my first PC, about as much storage space and it's ridiculous how bad (slow, unwieldy) the software is and it's not one phone or one manufacturer.
What keeps the (to me) obvious software functionality vacuum on a capable hardware platform from being filled up?