Hello!
I just updated to 1.5 and my Minecraft just stops working, this has never happened before.

First, I just open the Launcher, then I click "Login".
After that I see the Mojang logo on startup.
It takes more than usual...

After the Mojang logo, it just crashes!

Here is the crash report that I found in the .txt:
---- Minecraft Crash Report ----
// Don't be sad. I'll do better next time, I promise!

Time: 2013-03-13 17:11
Description: Failed to start game

java.lang.NullPointerException
at java.io.Reader.<init>(Unknown Source)
at java.io.InputStreamReader.<init>(Unknown Source)
at bp.a(SourceFile:64)
at bp.a(SourceFile:100)
at net.minecraft.client.Minecraft.a(SourceFile:250)
at avp.a(SourceFile:56)
at net.minecraft.client.Minecraft.run(SourceFile:505)
at java.lang.Thread.run(Unknown Source)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– System Details –
Details:
Minecraft Version: 1.5
Operating System: Windows 7 (x86) version 6.1
Java Version: 1.7.0_09, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
Memory: 389214792 bytes (371 MB) / 518979584 bytes (494 MB) up to 1037959168 bytes (989 MB)
JVM Flags: 2 total; -Xms512m -Xmx1024m
AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
Suspicious classes: No suspicious classes found.
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
LWJGL: 2.4.2
OpenGL: Intel(R) HD Graphics Family GL version 3.0.0 - Build 8.15.10.2266, Intel
Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Texture Pack: Default
Profiler Position: N/A (disabled)
Vec3 Pool Size: ~_ERROR~ NullPointerException: null