Catalin on 2D Skeletal Animations
Catalin “Too Proud To Self-promote” Zima (you might know him as our local XNA MVP Captain ZSquare) has a nice write-up of 2D Skeletal Animations over at his blog. So, if you ever wondered what the benefits of skeletal animations in the 2D world as compared to our beloved sprite sheets are, his post would be your starting point to explore this very topic.
Screen-space deformations in XNA for Windows Phone 7
Captain ZSquare shares his technique to do screen-space deformations on Windows Phone 7. Introduces Catalin:
Working on our games, we came across the need to do some screen-space deformations for all sorts of special effects like explosions, ‘drunk filter’, warp effects and other similar stuff. But since we’re targeting Windows Phone 7, we don’t have access to any custom shaders (which is a bummer), so we had to be creative. In the end, the solution turned out to be rather simple, and the performance is good enough (if you don’t go overboard with the effects, of course).
See the post for screen shoots and code!
Lets see if Captain ZSquare reposts this one with a screen shoot, too 
XNA 4.0 Light Pre-Pass
Jorge Coluna posted an article on his site about implementing the Light Pre-Pass technique for rendering in XNA 4.0
Read all about it here.
XNA 4.0 Light Pre-Pass
Jorge Coluna shares the code and an article of his Light Pre-Pass technique for XNA 4.0. Says the Jorge:
The discussion between pros and cons of different techniques for real-time lighting has been running for years. Forward rendering, deferred shading and light pre-pass are some of the most famous techniques nowadays. Their definitions and variations can be found with a simple search on internet, with all the most complex mathematics, notations and formulas possible. Therefore I will not focus on this.
Whoa… long time no see
Sorry for the long absence
Anyway, here's some news:
Miscellany Tips for Working With a WP7 Device for the First Time, by Michael B. McLaughlin
Compressed GPU data formats, by The Shawn
Viewing Windows Phone 7 Marketplace on the simulator, by David Amador
XNA Tile Engine Base Solution for WP7
Gareth Williams has posted news of his Tile Engine solution for XNA which runs on Windows Phone 7.
And a handy list of all the features of the solution:
- Suitable for side-on and top-down games
- Good for platformers, RPGs, shooters, racers, adventures - anything that needs tiles!
- Works in landscape or portrait with one line change.
- Built on the Windows Phone 7 XNA Gamestate Management engine sample.
- Uses Nick Gravelyn's content pipeline extension for the "Tiled" editor.
- Simple but flexible camera class that clamps to the map boundaries.
- Draw the whole map at once, or one layer at a time for flexibility.
- Parallax scrolling simply by adding a couple of properties to a layer in Tiled.
- An overload to draw a layer as "shadows" by drawing offset+black+semi-transparent.
- Per-pixel colour-based collision detection on specified layers/tilesets.
There's a link to the sample project on his blog, please read the rest of this post along with trying out the sample.
Source
Article : Sun- and Lens Flare as a Post Process
by Charles Humphrey
Now this sample has come from my current XNA toy which is the Blacksun engine I am currently writing in XNA 3.1. It uses deferred lighting, instancing and a post processing framework that I found on a great site here, all I had to do was make it engine ready.
If you want to have a look at the effect in the engine you can see it here.
This sample is just one of the elements from the post processing framework in the engine, there are none of the other goodies in this sample, just the Sun post process. This sample has also been created using the XNA 4.0 CTP, so I only had one render target to work with at the time. This means that you can't see the sun being culled behind objects in the scene as I can't create a depth map as well as the rendered scene, to be honest, I still don't have that bit of the shader 100% anyway 
Placeholder in Games
Barnaby Smith shares his thoughts about using placeholder assets during the development of games:
Creation and use of placeholders, whether levels, 3d models, sprites or sounds, has a number of advantages when developing computer games. In this article I discuss some aspects of the use of placeholders in games.
Render Target Changes in XNA Game Studio 4.0
The Shawn of Hargreaves details the changes to the render target API in XNA Framework 4.0. The high level summary of these changes are:
RenderTarget2Dinherits fromTexture2DandRenderTargetCubefromTextureCubeto properly denote the Is-a in the API (no moreRenderTarget*.GetTexture())- Multiple render targets are set at once without explicitly specifying its index and all previous set render targets are unset automatically
- An optional depth buffer for a render target is now a property of the render target itself, which might be shared across multiple render targets if certain conditions are met
For the motivation and details of these changes see Rendertarget changes in XNA Game Studio 4.0.
HOWTO: Resolution Independent Rendering in 2D
David Amador shares his code to work with a fixed resolution on Windows without having to manage the placement of your renderables yourself. Sez David:
Independent Resolution Rendering?? What’s this all about?
Basically a way of not caring what you resolution is. Ever had Gui elements misplaced because you changed the resolution? Or getting out of the screen?
If you are doing a game on Xna just for Xbox360 you can basically use a 1280×720 base resolution and the Xbox will scale the game for you making the proper Letterbox.
But what about on Windows? Or if you use a different resolution on the Xbox? You have to manage that yourself.
I’ve made a small example on how to achieve this.