diff --git a/ChangeLog b/ChangeLog
index 44143405e..d363f4b60 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,9 +2,22 @@
 astroid's ChangeLog
 ===================
 
+
+What's New in astroid 3.1.0?
+============================
+Release date: TBA
+
+
+
+What's New in astroid 3.0.1?
+============================
+Release date: TBA
+
+
+
 What's New in astroid 3.0.0?
 =============================
-Release date: TBA
+Release date: 2023-09-25
 
 * Add support for Python 3.12, including PEP 695 type parameter syntax.
 
@@ -14,6 +27,14 @@ Release date: TBA
 
   Refs #2137
 
+* Use the global inference cache when inferring, even without an explicit
+  ``InferenceContext``. This is a significant performance improvement given how
+  often methods default to ``None`` for the context argument. (Linting ``astroid``
+  itself now takes ~5% less time on Python 3.12; other projects requiring more
+  complex inference calculations will see greater speedups.)
+
+  Refs #529
+
 * Following a deprecation period starting in astroid 2.7.0, the ``astroid.node_classes``
   and ``astroid.scoped_nodes`` modules have been removed in favor of ``astroid.nodes.node_classes``
   and ``astroid.nodes.scoped_nodes``.
@@ -72,14 +93,6 @@ Release date: TBA
   Closes pylint-dev/pylint#7464
   Closes pylint-dev/pylint#8074
 
-* Use the global inference cache when inferring, even without an explicit
-  ``InferenceContext``. This is a significant performance improvement given how
-  often methods default to ``None`` for the context argument. (Linting ``astroid``
-  itself now takes ~5% less time on Python 3.12; other projects requiring more
-  complex inference calculations will see greater speedups.)
-
-  Refs #529
-
 * Fix interrupted ``InferenceContext`` call chains, thereby addressing performance
   problems when linting ``sqlalchemy``.
 
@@ -225,7 +238,12 @@ Release date: TBA
 
 What's New in astroid 2.15.8?
 =============================
-Release date: TBA
+Release date: 2023-09-26
+
+* Fix a regression in 2.15.7 for ``unsubscriptable-object``.
+
+  Closes #2305
+  Closes pylint-dev/pylint#9069
 
 * Fix a regression in 2.15.7 for ``unsubscriptable-object``.
 
diff --git a/astroid/__pkginfo__.py b/astroid/__pkginfo__.py
index 3373449a2..ee9bd2e9d 100644
--- a/astroid/__pkginfo__.py
+++ b/astroid/__pkginfo__.py
@@ -2,5 +2,5 @@
 # For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE
 # Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt
 
-__version__ = "3.0.0b1-dev0"
+__version__ = "3.1.0-dev0"
 version = __version__
diff --git a/doc/upgrade_guide.rst b/doc/upgrade_guide.rst
deleted file mode 100644
index 79c57496f..000000000
--- a/doc/upgrade_guide.rst
+++ /dev/null
@@ -1,11 +0,0 @@
-===============
-Upgrade guide
-===============
-
-To ease the transition between major releases, the following page describes some of the breaking
-changes between major release and what to change to safely upgrade.
-
-Upgrading from ``astroid`` ``2.x`` to ``3.0``
----------------------------------------------
-
-- Work in progress
diff --git a/doc/whatsnew.rst b/doc/whatsnew.rst
index b30ebc4fb..e26a3c7b5 100644
--- a/doc/whatsnew.rst
+++ b/doc/whatsnew.rst
@@ -8,5 +8,4 @@ The "Changelog" contains *all* nontrivial changes to astroid for the current ver
 .. toctree::
    :maxdepth: 2
 
-   upgrade_guide
    changelog
diff --git a/tbump.toml b/tbump.toml
index 9662dc361..6e61fd6b1 100644
--- a/tbump.toml
+++ b/tbump.toml
@@ -1,7 +1,7 @@
 github_url = "https://github.com/pylint-dev/astroid"
 
 [version]
-current = "3.0.0b1-dev0"
+current = "3.1.0-dev0"
 regex = '''
 ^(?P<major>0|[1-9]\d*)
 \.