To be clear, this part is pure speculation. I understand that Next already has an excellent email client. Connecting it with other net-based apps will be a high priority. A time of great opportunity To win, Apple must continue to make it clear that the Mac platform has their full support. The stronger the connection the safer Apple will be.
Some energy is sure to dissipate.
Apple's mission must be to minimize the dissipation. Learn from history. Apple was able to transition much of the Apple II installed base to the Macintosh. But the System 7 transition took more than three years. Very few Mac users are using Newton.