This appears to be a widespread problem for rawhide users.

[root@newcaprica vmware]# rpm -q --qf '%{name}-%{version}-%{release}.%{arch}\n' tcl
tcl-8.4.13-14.fc7.x86_64

[root@newcaprica vmware]# yum update
Loading "installonlyn" plugin
Setting up Update Process
Resolving Dependencies
--> Running transaction check
Checking deps for tcl.x86_64 1-8.4.13-14.fc7 - None
---> Package tcl.x86_64 1:8.4.13-16.fc7 set to be updated
Checking deps for tcl.x86_64 1-8.4.13-16.fc7 - u

Dependencies Resolved

=============================================================================
 Package                 Arch       Version          Repository        Size 
=============================================================================
Updating:
 tcl                     x86_64     1:8.4.13-16.fc7  development       1.8 M

Transaction Summary
=============================================================================
Install      0 Package(s)         
Update       1 Package(s)         
Remove       0 Package(s)         

Total download size: 1.8 M
Is this ok [y/N]: y
Downloading Packages:
(1/1): tcl-8.4.13-16.fc7. 100% |=========================| 1.8 MB    00:04     
Running Transaction Test
Finished Transaction Test
Transaction Test Succeeded
Running Transaction
  Updating  : tcl                          ######################### [1/2] 
error: unpacking of archive failed on file /usr/lib64/tcl8.4: cpio: rename

Updated: tcl.x86_64 1:8.4.13-16.fc7
Complete!