To clarify further for those unfamiliar with the language,a super literal translation of "watashi wa hanbaga desu" is something like:
(concerning/as for) myself, (it's) hamburger.
On it's own if Bob says this, basically it comes out as "I (am) (a) hamburger".
However, if Sally has just said something like "I'll have a salad...what about you Bob?" then it makes sense as Bob's order is the implied subject and it becomes "My order is hamburger." or "I'll have hamburger."
I know very little about linguistics but I think there are a bunch of other things that make Japanese-English difficult to translate via software as well.
There is the whole aspect of culture embedded in it. あなた could mean "you" or something like "dear/sweetie" depending on the context. There also the question of how to translate "you" (etc) in English text to Japanese as you have to consider politeness etc. If you are just translating a business web page it's probably safe to stick with polite forms, but if you are translating say the dialogue in a TV show you want to preserve the tone of the characters.
In terms of voice recognition, Japanese seems to have a lot of homophones to me when compared to English. It may just be my imagination, but here are some I ran into recently:
舶,錘, 頭, 摘む, 積む, 詰む, and 紡錘 are all pronounced つむ and mean completely different things. Or 六, 碌, and 録 are pronounced ろく. 上, 神, 紙, 髪, and 加味 are all pronounced かみ.
I seem to run into things like that regularly; when just hearing it spoken you need the context to figure out what they mean.