So, if it made 46m friday-business, that would mean around 93% of Spidey 3's day business. If it follows Spidey's drops it would go on to gross around 152m for the weekend. That's the high end, I think, basing on these numbers.
New Moon didn't increase. It decresed about 10%. Then you have to remember it played on a lot less screens than The Hunger Games also, so it definetely isn't a safe bet that it will increase.