Infinity Ward has kept up the PC version of Call of Duty 4 updated regularly with patches; up until this point. From rumors circulating online it would appear that there will be no 1.8 patch coming to Call of Duty 4 PC players unless a huge exploit or monumental change to the game occurs.
Console players are also going to be out of updates after the new game types and playlists are updated.

This is disappointing given how well received the 1.7 patch/map pack was. It is also troublesome because a number of obvious glitches still exist in the game, the G3 knifing bug and various wall glitches to name a few. The PC version of the game also totally lacks the new kill cams that console players got, which were supposed to be released in the 1.7 patch but were pulled at the last second due to technical difficulties. This is by no means signals the death of Call of Duty 4 though, the game continues to be wildly popular on both the console and PC. This will likely remain true even after Call of Duty: World at War comes out, just based on how popular COD2 still is.

Just a few weeks after the 1.6 patch we have the Call of Duty 4 1.7 patch for PC players.

Click to Download the Call of Duty 4 1.7 Patch.

Here is exactly what the patch changes; it corrects an problem that allowed Call of Duty players to mess with console dvars on multiplayer server matches. It fixes a crash that happens when a Sabotage matches on Chinatown are tied and go into over time. Finally it corrects a language error where game icons would show up in English even if the original copy of the game was in a different language. Again no huge changes to the video game Call of Duty 4 but it is important to download it so you can play on all servers and so the video game runs more smoothly.