I noticed the URL embedded in a number of objects in Object Repository for test case(s). Does any one know if the same test case is run in another environment, will the object URLs get replaced or does the test case have to be re-recorded in that new environment?
No, they won’t get replaced unless you have code that specifically modifies properties of the TestObject(s). See:
The best approach is to not store full URLs in your TestObjects. Store your URLs in GlobalVariables per project (in 5.3.x) and in Profiles in 5.4+