I'm putting together a list of those areas where Salesforce's UI isn't quite as instantaneous as it might appear. I hope the table below is fairly self-explanatory. Contact me if you can think of other areas where Salesforce exhibits delays, or your experience differs. Thanks!

 

Type	Example	Longest delay I’ve seen	Does Salesforce indicate the data is/will be delayed?
Change Set install	Installing a Change Set after receiving the "Change Set uploaded" email	<5 mins*	Yes
Content indexing	Searching for Content after uploading it	<30 mins	No
Content previews	Looking at a Content record’s "Preview" pane after uploading it	<30 mins	Yes
Dashboard recalculation	Clicking "Refresh Now" on a Dashboard	<10 mins	Yes
Forecasting	Looking at managers’ summary forecasts immediately after subordinates change their forecasts	<5 mins	Yes
Import Wizard	Uploading records via the Import Wizard	<10 mins	Yes
Record visibility recalculation	Viewing records in a multi-million-record org after deleting and recreating the entire Role Hierarchy	<6 hrs**	Yes
Replacing a picklist value	Using Salesforce's "Find and Replace Picklist" function to replace all occurrences of one picklist value with another	a few hours	No
Rollup Summary Fields	Looking at a RSF’s value after it’s created	<5 mins	Yes
Sandbox refresh	Refreshing and reactivating a Sandbox org	<48 hrs	Yes
Search indexing	Searching for a record after creating it	<5 mins	No
Web-to-Case	Auto-matching to a Contact after receiving a Case	<5 mins***	No
Web-to-Lead	Seeing a Lead after a user fills out a web form	<5 mins	No

* Andrew Rouse reports seeing delays of up to an hour during the Winter '14 rollout.

** assuming Group Membership and Sharing Rule calculations are deferred.

*** props to Dan Watt

Thanks to Imran Kabir and Erica Bell for the feedback!