In the new Pidgin, there is no longer separate status icons per protocol. It's been unified so all "available" look the same, all "away" look the same, etc. If you don't like the plain green circle that they use for available, though, you can change it. The status icons should be in /usr/local/share/pixmaps/pidgin/status. They're separated by size. Simply replace the icons with the ones you want to use (use the same names) and restart Pidgin. /usr/local is where anything that didn't come from the distro goes. I've changed mine to use a slightly modified (to include more colors) version of Zicklepop's Gummy Bear theme. I suggest checking out some of his other themes.
You can change any of the icons you want. They're all in that same part of the file system. If you want to add more smiley themes, that's in /usr/local/share/pixmaps/pidgin/emotes. To change the center toolbar's icons on IM windows (where it lets you pick font color or insert an image), look in pidgin/toolbar. The little icons that show next to a person's buddy icon on the buddy list and show if it's a cell phone, sidekick, etc. are in pidgin/emblems. When you hover your mouse over a person in your buddy list, since the protocol isn't shown on the left (it shows the status instead), a little protocol icon shows next to the buddy icon. If you have some people which are on multiple protocols and group them together, expanding the person will show the protocol icons as well. These are in pidgin/protocols if you want to modify them. If you want to change what shows in your notification area, look in pidgin/tray. You can set the old Gaim logos in there if you want it to look like that, or make it look like MSN Messenger or Yahoo IM or whatever you want.