I'm pretty sure we won't see an actual 1020 successor tomorrow. Most signs lead to the known 630, as well as a 920/925 successor - the 930. Which most likely will be some sort of international version of the Lumia Icon. So for people who still want that camera, there won't be any device tomorrow to really get them excited.
Besides the 1020 still ain't no bad phone, the internals might not be the freshest anymore, but IMO it is more than capable of still handling all daily tasks very well. Sure battery life really could be better, but there are some ways to try workarounds like external batteries. I got my 1020 almost four weeks ago, with having the knowledge we'll see some new devices a month later and I don't regret it. I also got the phone for the camera as being the number one reason.
Last but not least, regardless of what is being announced tomorrow. The 1020 is a phone you can get today, who knows when the new toys are going to be available in the stores. It's highly unlikely we would be able to buy the new stuff sometime next week.