Europe as a whole went to the Euro as a way to have uniformity in money to begin with. Germany is a large world power as well as a economical beacon, so their abandonment of the Euro would most likely cause some confusion and trouble when dealing with world markets, as well as the the fact that it would be expensive to convert to another form of money.
Although I see a downfall of the Euro soon, I don't think countries should do this to other European countries so quickly. Germany dropping the Euro would bring a cascade of abandonments in the other European countries and quickly this will turn into recession in my opinion. It would be to the best of Germany in the short run, but the impact it does to other countries in the long run will prove a bad decision for Germany.
Germany should stay with the Euro. It is a most convenient way for people traveling throughout Europe to pay for everything from a train trip to a meal at a restaurant. Before the introduction of the Euro people had to stop at the border of each country to exchange their Dutch guilders for French francs, or their Austrian schillings for Spanish pesetas. Often there wasn't a true 'translation' from one currency to another and people ended up losing on each transaction. With the Euro all that is taken care of and there is only convenience.
Germany should not abandon the Euro, despite being the strongest financially in the EU. Germany has committed themselves to the Union, and the Euro. As a result they are stuck being the financial back bone of the European Union. If they were to stop using the Euro they would essential put Europe into a huge, crushing financial crisis.