After installing MariaDB from .deb files (assuming all fixes to preceding bugs are applied and install succeeds), I get this:

root@ubuntu-x86-vm:~# ls -la /var/lib/mysql/
total 20564
drwxr-xr-x 4 mysql mysql 4096 2009-10-19 19:20 .
drwxr-xr-x 34 root root 4096 2009-10-19 19:19 ..
rw-rr- 1 root root 0 2009-10-19 19:19 debian-5.1.flag
rw-rw--- 1 mysql mysql 10485760 2009-10-19 19:20 ibdata1
rw-rw--- 1 mysql mysql 5242880 2009-10-19 19:20 ib_logfile0
rw-rw--- 1 mysql mysql 5242880 2009-10-19 19:19 ib_logfile1
rw-rw--- 1 mysql mysql 16384 2009-10-19 19:19 maria_log.00000001
rw-rw--- 1 mysql mysql 52 2009-10-19 19:19 maria_log_control
drwxr-xr-x 2 mysql root 4096 2009-10-19 19:20 mysql
rw------ 1 root root 17 2009-10-19 19:20 mysql_upgrade_info
rw-rw--- 1 mysql mysql 4 2009-10-19 19:19 pbxt-lock
drwx------ 2 root root 4096 2009-10-19 19:19 test

note that 'test' is owned by root. This makes it impossible to create any tables in 'test' database:

MySQL [test]> create table t1(a int);
ERROR 1005 (HY000): Can't create table 't1' (errno: 13)

MySQL [test]> create database db1;
Query OK, 1 row affected (0.00 sec)

MySQL [test]> create table db1.t1(a int);
Query OK, 0 rows affected (0.05 sec)

Fix suggestion: make the installation procedure set correct permissions.