That would be groovtacular, but
the WSDL marked "2_0" does not appear to offer such a filter. Here's the XML for that method's parameters struct:
<xs:complexType name="ParamsGetMultipleLeads">
<xs:sequence>
<xs:element name="leadSelector" type="tns:LeadSelector" minOccurs="0" maxOccurs="1" nillable="false"/>
<xs:element name="lastUpdatedAt" type="xs:dateTime" minOccurs="0" maxOccurs="1" nillable="false"/>
<xs:element name="streamPosition" type="xs:string" minOccurs="0" maxOccurs="1" nillable="true"/>
<xs:element name="batchSize" type="xs:int" minOccurs="0" maxOccurs="1" nillable="true"/>
<xs:element name="includeAttributes" type="tns:ArrayOfString" minOccurs="0" maxOccurs="1" nillable="false"/>
</xs:sequence>
</xs:complexType>
Being able to filter both start and end dates, and by date created or by date modified, would be very useful.