Description of problem:

Yum's status or error messages could be more precise. 


Version-Release number of selected component (if applicable):
yum-2.1.6-1

How reproducible:

Everytime

Steps to Reproduce:
1. run yum install packagename where package already exists
2. run yum install packagename for a non existant package

  
Actual results:

1. "Nothing to do" - Would be better to say "package already
installed" or something similar

2. argument does not exist - would be better to say "Package does not
exist in repository" or something similar