way to prevent queries from waiting for table level lock
The MyISAM Storage Engine is furiously notorious for performing full table locks for any DML (INSERTs, UPDATEs, DELETEs). InnoDB would definitely solve that issue in the long term.

I wrote about pros and cons of using MyISAM vs InnoDB


InnoDB vs MyISAM with many indexes (Jul 05, 2012)
Which is faster, InnoDB or MyISAM? (May 03, 2012)
Any gotchas at all with converting from MyISAM to InnoDB? (Jan 09, 2012)
Should I use a storage engine other than MyISAM to optimise these tables or should I get better disks? (Oct 07, 2011)
Benefits of table level locking (Sep 14, 2011)
What are the main differences between InnoDB and MyISAM? (Apr 14, 2011)


With regard to your current question, here is a possible scenario:


article and article_comments are both MyISAM tables
article_comments has one or more indexes with status as a column
Index page updates for article_comments are cached in the MyISAM Key Buffer (sized by key_buffer_size), causing old index pages out of the MyISAM Key Buffer
You have SELECT queries that perform JOINs between article and article_comments


In my suggested scenario, SELECTs against the article table can be held up from allowing writes because of having to wait for article_comments to be free from any DML (in this case, an UPDATE)