question about backup and restore with xtrabackup/innobackupex

few questions here.
I used to use innohotbackup which was pretty much seamless.
Xtrabackup seems to have a few kinks that I’m still trying to get used to.
First, I’m guessing innobackupex is the binary that needs to be used for a full, proper backup? just the xtrabackup binary itself does not backup .MYI files, .FRM files, mysql db. Why is that?

second,
I want to setup a cronjob to backup using innobackupex and I want the backup to go directly to a specific directory.
this is the command I would use;
innobackupex-1.5.1 --stream=tar ./ | gzip - > /data/test/backup.tar.gz
question about the above, what is the ./ for exactly? I tried changing that parameter with no affect.

To restore,
tar xvfi /data/test/backup.tar.gz
then
innobackupex-1.5.1 --apply-log --use-memory=4G --ibbackup=xtrabackup_51 /data/data/test

is this correct?
if ibbackup=xtrabackup_51 is not sepecified, and the mysql server is stopped the above command will fail with this error:
“Possible values are xtrabackup_51 (for MySQL 5.0 and 5.1) or xtrabackup (for MySQL 5.1 with InnoDB plugin or Percona Server)”
now, what if i’m using mysql 5.4 or 5.5 ? We plan on using 5.4 or 5.5 on our next release?

am I missing something?

tia

does anyone have an answer to this?

how to restore mysql 5.5 using innobackupex ?
Will this command “innobackupex-1.5.1 --apply-log --use-memory=4G --ibbackup=xtrabackup_51 /data/data/test” still work?
““Possible values are xtrabackup_51 (for MySQL 5.0 and 5.1) or xtrabackup (for MySQL 5.1 with InnoDB plugin or Percona Server)””

any ideas?

A 5.5 version of xtrabackup is in progress, please see http://www.mysqlperformanceblog.com/2010/12/13/percona-xtrab ackup-1-5-beta/