Gardening Advice

Can anyone come up with a good reason for why I should trash my current tomato plants and start new ones in a month or so?

I started two types of tomatoes last Spring and after some trial and error and advice figured out how to make them fruit. They're still producing (I chopped up 10 tiny tomatoes and put them in a stew yesterday). Currently there are 5 or 6 green tomatoes on the plants and a whole new crop of blossoms at the top of each plant.

However, my plan has always been to scrap my current plants and start afresh this Spring, armed with my increased gardening knowledge. But they're still alive and they're still producing. Jason suggested I just cut off the dead branches and keep these plants around for another season.

These plants produce teeny tiny tomatoes, which may be a result of my not pruning them enough, or because they're growing indoors. I planted another plant outside last year and the tomatoes on that plant were about twice the size as those from the indoor plants. I was kind of thinking I would tweak things this year and shoot for getting some bigger tomatoes indoors, but I don't know if I need to start all over again to do that.

I know outdoor gardeners don't really run into this issue since plants, you know, die in the winter. Any thoughts as to why I should or shouldn't keep these plants around for another season?