No, there aren't. The Colemak take on it is to keep the symbol keys as they are in the US layout – or change them to whatever suits you! Symbol/number keys just aren't a part of the core layout, which is nice because it gives modularity. (The exception to this is the semicolon key which has to be moved from its QWERTY position.)

There are, however, many cool mods out (see for instance my sig topics). The distance to the Enter key is improved with Wide mods, for instance. Also with the marvelous Extend mod! I think my Caps+O Backspace may be just as good as yours, without disrupting the apostrophe position? And the Caps+Space Enter flows very naturally for me.

Some design attempts have been made for coding-friendly AltGr mappings. The optimal coding layer(s) for you may depend on language usage, though.

Because you can't use any of the most popular keyboard mods as effectively, like Angle-mod, Wide-mod and others. I personally discovered the need for Angle-mod as a QWERTY typist, and I'm sure it affects Dvorak typists just as well. If anything, I'd recommend going Angle+Wide (fixing the ZXC angle, getting closer to Enter and Backspace and AltGr/R.Alt) regardless if you're a programmer or not.

Here's an example from Dreymar's bag of tricks:

I think from here you set yourself up to a much more effective layout. Unfortunately ANSI forces you to accept some annoying drawbacks when attempting these mods.

Bombdiggity, that's the most uninformed comment I've seen on these forums in ages. :-þ

Data5: Glad you like it! We aim to please.

Yes, make your own programmer layer using right-alt / AltGr!
As has been mentioned, with the wide mod this is better still.

Here is mine for reference:

Highlighted characters are dead keys for creating accents in the unlikely event I would need to type such a thing. I find the main benefit is the easy brackets on the home row -- it's worth it for that alone!