Another sci-fi (2040)

I just saw a video where Nicholas Negroponte shows his vision in 1984 and many of his predictions have come true today.
So, I just thought, "had I been Nicholas Negroponte, seeding a project so noble and purposeful as OLPC, and having seen my vision coming true in front of my own eyes, I would have lived the life I always wanted to."

Now let me imagine year 2040. Domestic robots have become a reality. They can cook food, drive cars (in case car can't drive itself), clean home, clothes and utensils, shop in from POSIX compatible grocery stores, maintain themselves, get themselves repaired and earn money by renting their services to those who can't yet afford robots.
Challenges to this vision:
1. Voice recognition: Voice recognition is erroneous and unreliable. 95% accuracy in a local area should be enough for commercial viability.
2. Batteries that can hold power to serve a robot for 16 hours. Either batteries need to be more powerful or robots need to be more power efficient.
3. Image recognition: Processing images seems to be quite slow. We need faster computers. If cars can drive themselves based on vision only, then we are ready.
4. Learning: How much self-learning we need to introduce machines to the domestic environment ? May be we can do without self learning. Machines can be pre-programmed to do these kind of stuffs and auto-install from open repositories.