Yes.  There are some issues for PCs with non-standard set-ups.
I had some problems with IE7-RC1, so I made sure of a few things before installing.
IE7 installed smoothly last night!!
MY RECOMMENDATIONS for things to do before you install IE7.
(a) Set a Restore Point, just in case.
(b) Make sure you current version of IE is the default browser [ ESSENTIAL ]
(c) Disable all firewalls and AV while installing.
(d) When asked by IE7 to check for latest updates, SAY NO.
(e) If you have changed IE Security Zone defaults, put both http://runonce.msn.com &
http://*.microsoft.com in the Trusted Zone.
(f) You need to be connected to the Internet during the installation.
INSTALLATION FEATURES AND SIDE EFFECTS.
(A) PC reboots twice during installation.
(B) QUICK LAUNCH Toolbar in task bar at the bottom of the screen was turned off by installation - Right click the toolbar, select Toolbasr / Quick launch to turn it back on.
(C) WithOut Warning, An RSS FEED (msnews.microsoft.com) was installed in my Email program(ThunderBird).
CONFIGURATION ISSUES
(a) The menu bar does not appear by default.  If you want it back, click the cog/wheel and select 'MenuBar' from the drop down menu.
(b)  You can now change you default search engine in IE.  In the top right there is a magnifying glass icon.  Left Click the arrow next to it, and choose 'FindMoreProviders', if you want.
(c)  Play with TAB BROWSING settings. click the Tools button / Internet Options / General tab, and then, in the Tabs section, click Settings.