Notes vs. Exchange

"Is Exchange a Notes killer?" is a topic which has occupied people's minds since Microsoft first announced Exchange. The following features can be noted now that Exchange has finally been released:
1) Exchange is not a groupware development platform.
2) Exchange is primarily a messaging (e-mail) infrastructure.
3) Exchange doesn't have true replication (where clients can disconnect and remain productive as they can with Notes).
4) Notes has a built-in development environment whilst Exchange requires custom applications to be built with Visual Basic (or other tools that support extended MAPI).
5) Development time is shorter in Notes because of (4).

Here is a list of various articles available on-line on this subject:
Lotus' Comparisons
Microsoft's Comparisons
PC Magazine
PC Week article on Releasing the Power of Groupware
Internet Week article on Exchange 2000 vs. Notes

Comments from an Admin from a Large Gov. Agency
Creative Networks Analysis of Exchange vs. Notes Development
Comments from an Admin who had to migrate to Exchange