wow, congrats to everyone!
It is a shock at first, and I don't think I personally really got completely over it til a good while after they were born! I got used to the pregnancy bit then when they were born it was strange all over again looking at TWO babies instead of one!
It is hard work, but you find ways of dealing with things, and I think the best advice is to take it one day at a time, and follow your instincts. Don't expect to parent in the same way as with a singleton, when you have two to consider, and don't compare yourself to singleton mums.
Rest as much as you can during the pg, cos you won't get much for a little while after.
mamachris, my older two were 4 and 2 when my twins were born. They did occassionally feel a bit left out, but we had to deal with it best we can and get on with it. Now, they are 9 and 7, the twins are nearly 5 and it was def worth it. They are all very close and generally play together well. There are def advantages to having lots close enough in age to share interests. Congrats!