Thanks to quite a few anonymous tipsters who sent this in! OS 4.5.0.69 for the 8310 has been spotted all over the interweb.
For example:
Here & Here
NOTE: Do not install this software if you do not know what you are doing. It may make your BlackBerry FUBAR or just plain angry.

 Telstra Australia has released the first of the v4.5.0.xx firmware for their 8310 devices today. Hopefully this will be the first of many of the new operating system upgrades across all networks in Australia. You can get the upgrade at this link; Download
Source; BlackBerry Forums Australia.

Mo just let me know that Bplay has released a slick new FlowBerry theme to follow up on their ground breaking crossbar theme. The theme has a slick coverflow-like menu bar that just looks awesome. Sadly you can not configure the coverflow menu yourself but it does include: Messages, Calendar, Address Book, Media, SMS, BlackBerry [...]

Stefano spotted this hot new theme by Sasha on Themes4BB. This one is OS 4.5 only and looks positively gorgeous on my 8300. The main menu is 6 icons spaced out in a circle which looks really slick. The top menu is nice, simple, and easy to read. The icons are from the Bold and [...]

Just got an anonymous tip from an anonymous reader (Lets call him Mr J). They found OS 4.5.0.55 online for the 8320. The 8320 has been having a rough time with OS releases but hopefully this latest version will work out.
One example of where 4.5.0.55 can be found is at this link:
http://rapidshare.com/files/132732724/8320AllLang_PBr4.5.0_rel81_PL2.7.0.68_A4.5.0.55.exe.html
NOTE: Do not install [...]

Mistabyggs from Themes4bb.com has recently created a great looking FREE theme for 8300 Blackberry Devices running OS 4.5. The theme is called Aurora Blue Bottom Dock and boasts the famous Blackberry symbol as a watermark in the background of it’s vibrant blue screen. Top header is very clean and simple, and battery indicator shows bars [...]

Cmccrary released a slick new theme using the new Plazmic CDK. He created the same theme in a couple different variations. Different strokes and all. The themes look nice and clean and the blue highlighting actually looked pretty good with a couple of my Backgrounds. Nothing extravagant but still shows off what you can do [...]

Michael Small just let me know that he published 4 different themes created with the new Plazmic 4.5 beta. These themes require OS 4.5 which is a bummer but they look pretty cool.
Check out some of them below:

You can download them at this link but sadly they are desktop manager installation only.

Josep let me know about a free theme by Xorphan on PinStack that really shows off the new Plazmic 4.5 CDK. The theme is called X-Blue and is very cutting edge. It has an upside-down “T” of icons on the main page that looks slick. The top bar is nice and simple and will go [...]

MonkeyBizIU, a frequent poster at Pinstack.com, has created a cool looking theme called ‘BoldBerry’ for the 81xx and 83xx Blackberry devices. The theme uses the Blue futuristic background and icons we’ve seen on some of the earlier Blackberry Bold images floating around on the net. I must say, this is probably one of the best [...]